diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index a0f53af981..06fa45818e 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -11,6 +11,8 @@ LMS: Add support for user partitioning based on cohort.  TNL-710
 
 Platform: Add base support for cohorted group configurations.  TNL-649
 
+LMS: Support assigning students to cohorts via a CSV file upload. TNL-735
+
 Common: Add configurable reset button to units
 
 Studio: Add support xblock validation messages on Studio unit/container page. TNL-683
diff --git a/common/djangoapps/student/management/commands/create_random_users.py b/common/djangoapps/student/management/commands/create_random_users.py
index 5ad55db7be..088d4484ab 100644
--- a/common/djangoapps/student/management/commands/create_random_users.py
+++ b/common/djangoapps/student/management/commands/create_random_users.py
@@ -1,12 +1,27 @@
 """
 A script to create some dummy users
 """
+import uuid
+
 from django.core.management.base import BaseCommand
 from student.models import CourseEnrollment
 from opaque_keys import InvalidKeyError
 from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
-from student.views import _do_create_account, get_random_post_override
+from student.views import _do_create_account
+
+
+def get_random_post_override():
+    """
+    Generate unique user data for dummy users.
+    """
+    identification = uuid.uuid4().hex[:8]
+    return {
+        'username': 'user_{id}'.format(id=identification),
+        'email': 'email_{id}@example.com'.format(id=identification),
+        'password': '12345',
+        'name': 'User {id}'.format(id=identification),
+    }
 
 
 def create(num, course_key):
diff --git a/common/djangoapps/util/file.py b/common/djangoapps/util/file.py
new file mode 100644
index 0000000000..25d2bc9b63
--- /dev/null
+++ b/common/djangoapps/util/file.py
@@ -0,0 +1,168 @@
+"""
+Utility methods related to file handling.
+"""
+
+from datetime import datetime
+import os
+from pytz import UTC
+
+from django.core.exceptions import PermissionDenied
+from django.core.files.storage import DefaultStorage, get_valid_filename
+from django.utils.translation import ugettext as _
+from django.utils.translation import ungettext
+
+
+class FileValidationException(Exception):
+    """
+    An exception thrown during file validation.
+    """
+    pass
+
+
+def store_uploaded_file(
+        request, file_key, allowed_file_types, base_storage_filename, max_file_size, validator=None,
+):
+    """
+    Stores an uploaded file to django file storage.
+
+    Args:
+        request (HttpRequest): A request object from which a file will be retrieved.
+        file_key (str): The key for retrieving the file from `request.FILES`. If no entry exists with this
+            key, a `ValueError` will be thrown.
+        allowed_file_types (list): a list of allowable file type extensions. These should start with a period
+            and be specified in lower-case. For example, ['.txt', '.csv']. If the uploaded file does not end
+            with one of these extensions, a `PermissionDenied` exception will be thrown. Note that the uploaded file
+            extension does not need to be lower-case.
+        base_storage_filename (str): the filename to be used for the stored file, not including the extension.
+            The same extension as the uploaded file will be appended to this value.
+        max_file_size (int): the maximum file size in bytes that the uploaded file can be. If the uploaded file
+            is larger than this size, a `PermissionDenied` exception will be thrown.
+        validator (function): an optional validation method that, if defined, will be passed the stored file (which
+            is copied from the uploaded file). This method can do validation on the contents of the file and throw
+            a `FileValidationException` if the file is not properly formatted. If any exception is thrown, the stored
+            file will be deleted before the exception is re-raised. Note that the implementor of the validator function
+            should take care to close the stored file if they open it for reading.
+
+    Returns:
+        Storage: the file storage object where the file can be retrieved from
+        str: stored_file_name: the name of the stored file (including extension)
+
+    """
+
+    if file_key not in request.FILES:
+        raise ValueError("No file uploaded with key '" + file_key + "'.")
+
+    uploaded_file = request.FILES[file_key]
+    try:
+        file_extension = os.path.splitext(uploaded_file.name)[1].lower()
+        if not file_extension in allowed_file_types:
+            file_types = "', '".join(allowed_file_types)
+            msg = ungettext(
+                "The file must end with the extension '{file_types}'.",
+                "The file must end with one of the following extensions: '{file_types}'.",
+                len(allowed_file_types)).format(file_types=file_types)
+            raise PermissionDenied(msg)
+
+        if uploaded_file.size > max_file_size:
+            msg = _("Maximum upload file size is {file_size} bytes.").format(file_size=max_file_size)
+            raise PermissionDenied(msg)
+
+        stored_file_name = base_storage_filename + file_extension
+
+        file_storage = DefaultStorage()
+        file_storage.save(stored_file_name, uploaded_file)
+
+        if validator:
+            try:
+                validator(file_storage, stored_file_name)
+            except:
+                file_storage.delete(stored_file_name)
+                raise
+
+    finally:
+        uploaded_file.close()
+
+    return file_storage, stored_file_name
+
+
+# pylint: disable=invalid-name
+def course_filename_prefix_generator(course_id, separator='_'):
+    """
+    Generates a course-identifying unicode string for use in a file
+    name.
+
+    Args:
+        course_id (object): A course identification object.
+    Returns:
+        str: A unicode string which can safely be inserted into a
+            filename.
+    """
+    return get_valid_filename(unicode(separator).join([course_id.org, course_id.course, course_id.run]))
+
+
+# pylint: disable=invalid-name
+def course_and_time_based_filename_generator(course_id, base_name):
+    """
+    Generates a filename (without extension) based on the current time and the supplied filename.
+
+    Args:
+        course_id (object): A course identification object (must have org, course, and run).
+        base_name (str): A name describing what type of file this is. Any characters that are not safe for
+            filenames will be converted per django.core.files.storage.get_valid_filename (Specifically,
+            leading and trailing spaces are removed; other  spaces are converted to underscores; and anything
+            that is not a unicode alphanumeric, dash, underscore, or dot, is removed).
+
+    Returns:
+        str: a concatenation of the org, course and run from the input course_id, the input base_name,
+            and the current time. Note that there will be no extension.
+
+    """
+    return u"{course_prefix}_{base_name}_{timestamp_str}".format(
+        course_prefix=course_filename_prefix_generator(course_id),
+        base_name=get_valid_filename(base_name),
+        timestamp_str=datetime.now(UTC).strftime("%Y-%m-%d-%H%M%S")  # pylint: disable=maybe-no-member
+    )
+
+
+class UniversalNewlineIterator(object):
+    """
+    This iterable class can be used as a wrapper around a file-like
+    object which does not inherently support being read in
+    universal-newline mode.  It returns a line at a time.
+    """
+    def __init__(self, original_file, buffer_size=4096):
+        self.original_file = original_file
+        self.buffer_size = buffer_size
+
+    def __iter__(self):
+        return self.generate_lines()
+
+    @staticmethod
+    def sanitize(string):
+        """
+        Replace CR and CRLF with LF within `string`.
+        """
+        return string.replace('\r\n', '\n').replace('\r', '\n')
+
+    def generate_lines(self):
+        """
+        Return data from `self.original_file` a line at a time,
+        replacing CR and CRLF with LF.
+        """
+        buf = self.original_file.read(self.buffer_size)
+        line = ''
+        while buf:
+            for char in buf:
+                if line.endswith('\r') and char == '\n':
+                    last_line = line
+                    line = ''
+                    yield self.sanitize(last_line)
+                elif line.endswith('\r') or line.endswith('\n'):
+                    last_line = line
+                    line = char
+                    yield self.sanitize(last_line)
+                else:
+                    line += char
+            buf = self.original_file.read(self.buffer_size)
+            if not buf and line:
+                yield self.sanitize(line)
diff --git a/common/djangoapps/util/tests/test_file.py b/common/djangoapps/util/tests/test_file.py
new file mode 100644
index 0000000000..ed50202151
--- /dev/null
+++ b/common/djangoapps/util/tests/test_file.py
@@ -0,0 +1,257 @@
+# -*- coding: utf-8 -*-
+"""
+Tests for file.py
+"""
+import ddt
+from io import StringIO
+
+from django.test import TestCase
+from datetime import datetime
+from django.utils.timezone import UTC
+from mock import patch, Mock
+from django.http import HttpRequest
+from django.core.files.uploadedfile import SimpleUploadedFile
+import util.file
+from util.file import (
+    course_and_time_based_filename_generator,
+    course_filename_prefix_generator,
+    store_uploaded_file,
+    FileValidationException,
+    UniversalNewlineIterator
+)
+from opaque_keys.edx.locations import CourseLocator, SlashSeparatedCourseKey
+from django.core import exceptions
+import os
+
+
+@ddt.ddt
+class FilenamePrefixGeneratorTestCase(TestCase):
+    """
+    Tests for course_filename_prefix_generator
+    """
+    @ddt.data(CourseLocator, SlashSeparatedCourseKey)
+    def test_locators(self, course_key_class):
+        self.assertEqual(
+            course_filename_prefix_generator(course_key_class(org='foo', course='bar', run='baz')),
+            u'foo_bar_baz'
+        )
+
+    @ddt.data(CourseLocator, SlashSeparatedCourseKey)
+    def test_custom_separator(self, course_key_class):
+        self.assertEqual(
+            course_filename_prefix_generator(course_key_class(org='foo', course='bar', run='baz'), separator='-'),
+            u'foo-bar-baz'
+        )
+
+
+@ddt.ddt
+class FilenameGeneratorTestCase(TestCase):
+    """
+    Tests for course_and_time_based_filename_generator
+    """
+    NOW = datetime.strptime('1974-06-22T01:02:03', '%Y-%m-%dT%H:%M:%S').replace(tzinfo=UTC())
+
+    def setUp(self):
+        datetime_patcher = patch.object(
+            util.file, 'datetime',
+            Mock(wraps=datetime)
+        )
+        mocked_datetime = datetime_patcher.start()
+        mocked_datetime.now.return_value = self.NOW
+        self.addCleanup(datetime_patcher.stop)
+
+    @ddt.data(CourseLocator, SlashSeparatedCourseKey)
+    def test_filename_generator(self, course_key_class):
+        """
+        Tests that the generator creates names based on course_id, base name, and date.
+        """
+        self.assertEqual(
+            u'foo_bar_baz_file_1974-06-22-010203',
+            course_and_time_based_filename_generator(course_key_class(org='foo', course='bar', run='baz'), 'file')
+        )
+
+        self.assertEqual(
+            u'foo_bar_baz_base_name_ø_1974-06-22-010203',
+            course_and_time_based_filename_generator(
+                course_key_class(org='foo', course='bar', run='baz'), ' base` name ø '
+            )
+        )
+
+
+class StoreUploadedFileTestCase(TestCase):
+    """
+    Tests for store_uploaded_file.
+    """
+
+    def setUp(self):
+        self.request = Mock(spec=HttpRequest)
+        self.file_content = "test file content"
+        self.request.FILES = {"uploaded_file": SimpleUploadedFile("tempfile.csv", self.file_content)}
+        self.stored_file_name = None
+        self.file_storage = None
+        self.default_max_size = 2000000
+
+    def tearDown(self):
+        if self.file_storage and self.stored_file_name:
+            self.file_storage.delete(self.stored_file_name)
+
+    def verify_exception(self, expected_message, error):
+        """
+        Helper method to verify exception text.
+        """
+        self.assertEqual(expected_message, error.exception.message)
+
+    def test_error_conditions(self):
+        """
+        Verifies that exceptions are thrown in the expected cases.
+        """
+        with self.assertRaises(ValueError) as error:
+            store_uploaded_file(self.request, "wrong_key", [".txt", ".csv"], "stored_file", self.default_max_size)
+        self.verify_exception("No file uploaded with key 'wrong_key'.", error)
+
+        with self.assertRaises(exceptions.PermissionDenied) as error:
+            store_uploaded_file(self.request, "uploaded_file", [], "stored_file", self.default_max_size)
+        self.verify_exception("The file must end with one of the following extensions: ''.", error)
+
+        with self.assertRaises(exceptions.PermissionDenied) as error:
+            store_uploaded_file(self.request, "uploaded_file", [".bar"], "stored_file", self.default_max_size)
+        self.verify_exception("The file must end with the extension '.bar'.", error)
+
+        with self.assertRaises(exceptions.PermissionDenied) as error:
+            store_uploaded_file(self.request, "uploaded_file", [".xxx", ".bar"], "stored_file", self.default_max_size)
+        self.verify_exception("The file must end with one of the following extensions: '.xxx', '.bar'.", error)
+
+        with self.assertRaises(exceptions.PermissionDenied) as error:
+            store_uploaded_file(self.request, "uploaded_file", [".csv"], "stored_file", 2)
+        self.verify_exception("Maximum upload file size is 2 bytes.", error)
+
+    def test_validator(self):
+        """
+        Verify that a validator function can throw an exception.
+        """
+        validator_data = {}
+
+        def verify_file_presence(should_exist):
+            """ Verify whether or not the stored file, passed to the validator, exists. """
+            self.assertEqual(should_exist, validator_data["storage"].exists(validator_data["filename"]))
+
+        def store_file_data(storage, filename):
+            """ Stores file validator data for testing after validation is complete. """
+            validator_data["storage"] = storage
+            validator_data["filename"] = filename
+            verify_file_presence(True)
+
+        def exception_validator(storage, filename):
+            """ Validation test function that throws an exception """
+            self.assertEqual("error_file.csv", os.path.basename(filename))
+            with storage.open(filename, 'rU') as f:
+                self.assertEqual(self.file_content, f.read())
+            store_file_data(storage, filename)
+            raise FileValidationException("validation failed")
+
+        def success_validator(storage, filename):
+            """ Validation test function that is a no-op """
+            self.assertEqual("success_file.csv", os.path.basename(filename))
+            store_file_data(storage, filename)
+
+        with self.assertRaises(FileValidationException) as error:
+            store_uploaded_file(
+                self.request, "uploaded_file", [".csv"], "error_file",
+                self.default_max_size, validator=exception_validator
+            )
+        self.verify_exception("validation failed", error)
+        # Verify the file was deleted.
+        verify_file_presence(False)
+
+        store_uploaded_file(
+            self.request, "uploaded_file", [".csv"], "success_file", self.default_max_size, validator=success_validator
+        )
+        # Verify the file still exists
+        verify_file_presence(True)
+
+    def test_file_upload_lower_case_extension(self):
+        """
+        Tests uploading a file with lower case extension. Verifies that the stored file contents are correct.
+        """
+        self.file_storage, self.stored_file_name = store_uploaded_file(
+            self.request, "uploaded_file", [".csv"], "stored_file", self.default_max_size
+        )
+        self._verify_successful_upload()
+
+    def test_file_upload_upper_case_extension(self):
+        """
+        Tests uploading a file with upper case extension. Verifies that the stored file contents are correct.
+        """
+        self.request.FILES = {"uploaded_file": SimpleUploadedFile("tempfile.CSV", self.file_content)}
+        self.file_storage, self.stored_file_name = store_uploaded_file(
+            self.request, "uploaded_file", [".gif", ".csv"], "second_stored_file", self.default_max_size
+        )
+        self._verify_successful_upload()
+
+    def _verify_successful_upload(self):
+        """ Helper method that checks that the stored version of the uploaded file has the correct content """
+        self.assertTrue(self.file_storage.exists(self.stored_file_name))
+        with self.file_storage.open(self.stored_file_name, 'r') as f:
+            self.assertEqual(self.file_content, f.read())
+
+
+@ddt.ddt
+class TestUniversalNewlineIterator(TestCase):
+    """
+    Tests for the UniversalNewlineIterator class.
+    """
+    @ddt.data(1, 2, 999)
+    def test_line_feeds(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo\nbar\n'), buffer_size=buffer_size)],
+            ['foo\n', 'bar\n']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_carriage_returns(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo\rbar\r'), buffer_size=buffer_size)],
+            ['foo\n', 'bar\n']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_carriage_returns_and_line_feeds(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo\r\nbar\r\n'), buffer_size=buffer_size)],
+            ['foo\n', 'bar\n']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_no_trailing_newline(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo\nbar'), buffer_size=buffer_size)],
+            ['foo\n', 'bar']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_only_one_line(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo\n'), buffer_size=buffer_size)],
+            ['foo\n']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_only_one_line_no_trailing_newline(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'foo'), buffer_size=buffer_size)],
+            ['foo']
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_empty_file(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u''), buffer_size=buffer_size)],
+            []
+        )
+
+    @ddt.data(1, 2, 999)
+    def test_unicode_data(self, buffer_size):
+        self.assertEqual(
+            [thing for thing in UniversalNewlineIterator(StringIO(u'héllø wo®ld'), buffer_size=buffer_size)],
+            [u'héllø wo®ld']
+        )
diff --git a/common/static/js/spec_helpers/ajax_helpers.js b/common/static/js/spec_helpers/ajax_helpers.js
index 0b2769be57..3e51f91fd2 100644
--- a/common/static/js/spec_helpers/ajax_helpers.js
+++ b/common/static/js/spec_helpers/ajax_helpers.js
@@ -77,13 +77,20 @@ define(['sinon', 'underscore'], function(sinon, _) {
             JSON.stringify(jsonResponse));
     };
 
-    respondWithError = function(requests, requestIndex) {
+    respondWithError = function(requests, statusCode, jsonResponse, requestIndex) {
         if (_.isUndefined(requestIndex)) {
             requestIndex = requests.length - 1;
         }
-        requests[requestIndex].respond(500,
+        if (_.isUndefined(statusCode)) {
+            statusCode = 500;
+        }
+        if (_.isUndefined(jsonResponse)) {
+            jsonResponse = {};
+        }
+        requests[requestIndex].respond(statusCode,
             { 'Content-Type': 'application/json' },
-            JSON.stringify({ }));
+            JSON.stringify(jsonResponse)
+        );
     };
 
     respondToDelete = function(requests, requestIndex) {
diff --git a/common/test/acceptance/pages/lms/instructor_dashboard.py b/common/test/acceptance/pages/lms/instructor_dashboard.py
index f6dd4b45f1..5b251c7140 100644
--- a/common/test/acceptance/pages/lms/instructor_dashboard.py
+++ b/common/test/acceptance/pages/lms/instructor_dashboard.py
@@ -26,6 +26,37 @@ class InstructorDashboardPage(CoursePage):
         membership_section.wait_for_page()
         return membership_section
 
+    def select_data_download(self):
+        """
+        Selects the data download tab and returns a DataDownloadPage.
+        """
+        self.q(css='a[data-section=data_download]').first.click()
+        data_download_section = DataDownloadPage(self.browser)
+        data_download_section.wait_for_page()
+        return data_download_section
+
+    @staticmethod
+    def get_asset_path(file_name):
+        """
+        Returns the full path of the file to upload.
+        These files have been placed in edx-platform/common/test/data/uploads/
+        """
+
+        # Separate the list of folders in the path reaching to the current file,
+        # e.g.  '... common/test/acceptance/pages/lms/instructor_dashboard.py' will result in
+        #       [..., 'common', 'test', 'acceptance', 'pages', 'lms', 'instructor_dashboard.py']
+        folders_list_in_path = __file__.split(os.sep)
+
+        # Get rid of the last 4 elements: 'acceptance', 'pages', 'lms', and 'instructor_dashboard.py'
+        # to point to the 'test' folder, a shared point in the path's tree.
+        folders_list_in_path = folders_list_in_path[:-4]
+
+        # Append the folders in the asset's path
+        folders_list_in_path.extend(['data', 'uploads', file_name])
+
+        # Return the joined path of the required asset.
+        return os.sep.join(folders_list_in_path)
+
 
 class MembershipPage(PageObject):
     """
@@ -38,15 +69,39 @@ class MembershipPage(PageObject):
 
     def select_auto_enroll_section(self):
         """
-        returns the MembershipPageAutoEnrollSection
+        Returns the MembershipPageAutoEnrollSection page object.
         """
         return MembershipPageAutoEnrollSection(self.browser)
 
+    def select_cohort_management_section(self):
+        """
+        Returns the MembershipPageCohortManagementSection page object.
+        """
+        return MembershipPageCohortManagementSection(self.browser)
+
+
+class MembershipPageCohortManagementSection(PageObject):
+    """
+    The cohort management subsection of the Membership section of the Instructor dashboard.
+    """
+    url = None
+    csv_browse_button_selector = '.csv-upload #file-upload-form-file'
+    csv_upload_button_selector = '.csv-upload #file-upload-form-submit'
+
+    def is_browser_on_page(self):
+        return self.q(css='.cohort-management.membership-section').present
+
+    def _bounded_selector(self, selector):
+        """
+        Return `selector`, but limited to the cohort management context.
+        """
+        return '.cohort-management.membership-section {}'.format(selector)
+
     def _get_cohort_options(self):
         """
         Returns the available options in the cohort dropdown, including the initial "Select a cohort group".
         """
-        return self.q(css=".cohort-management #cohort-select option")
+        return self.q(css=self._bounded_selector("#cohort-select option"))
 
     def _cohort_name(self, label):
         """
@@ -89,7 +144,7 @@ class MembershipPage(PageObject):
         """
         Selects the given cohort in the drop-down.
         """
-        self.q(css=".cohort-management #cohort-select option").filter(
+        self.q(css=self._bounded_selector("#cohort-select option")).filter(
             lambda el: self._cohort_name(el.text) == cohort_name
         ).first.click()
 
@@ -97,45 +152,64 @@ class MembershipPage(PageObject):
         """
         Adds a new manual cohort with the specified name.
         """
-        self.q(css="div.cohort-management-nav .action-create").first.click()
-        textinput = self.q(css="#cohort-create-name").results[0]
+        self.q(css=self._bounded_selector("div.cohort-management-nav .action-create")).first.click()
+        textinput = self.q(css=self._bounded_selector("#cohort-create-name")).results[0]
         textinput.send_keys(cohort_name)
-        self.q(css="div.form-actions .action-save").first.click()
+        self.q(css=self._bounded_selector("div.form-actions .action-save")).first.click()
 
     def get_cohort_group_setup(self):
         """
         Returns the description of the current cohort
         """
-        return self.q(css='.cohort-management-group-setup .setup-value').first.text[0]
+        return self.q(css=self._bounded_selector('.cohort-management-group-setup .setup-value')).first.text[0]
 
     def select_edit_settings(self):
-        self.q(css=".action-edit").first.click()
+        self.q(css=self._bounded_selector(".action-edit")).first.click()
 
     def add_students_to_selected_cohort(self, users):
         """
         Adds a list of users (either usernames or email addresses) to the currently selected cohort.
         """
-        textinput = self.q(css="#cohort-management-group-add-students").results[0]
+        textinput = self.q(css=self._bounded_selector("#cohort-management-group-add-students")).results[0]
         for user in users:
             textinput.send_keys(user)
             textinput.send_keys(",")
-        self.q(css="div.cohort-management-group-add .action-primary").first.click()
+        self.q(css=self._bounded_selector("div.cohort-management-group-add .action-primary")).first.click()
 
     def get_cohort_student_input_field_value(self):
         """
         Returns the contents of the input field where students can be added to a cohort.
         """
-        return self.q(css="#cohort-management-group-add-students").results[0].get_attribute("value")
+        return self.q(
+            css=self._bounded_selector("#cohort-management-group-add-students")
+        ).results[0].get_attribute("value")
 
     def _get_cohort_messages(self, type):
         """
-        Returns array of messages for given type.
+        Returns array of messages related to manipulating cohorts directly through the UI for the given type.
         """
-        message_title = self.q(css="div.cohort-management-group-add .cohort-" + type + " .message-title")
+        title_css = "div.cohort-management-group-add .cohort-" + type + " .message-title"
+        detail_css = "div.cohort-management-group-add .cohort-" + type + " .summary-item"
+
+        return self._get_messages(title_css, detail_css)
+
+    def get_csv_messages(self):
+        """
+        Returns array of messages related to a CSV upload of cohort assignments.
+        """
+        title_css = ".csv-upload .message-title"
+        detail_css = ".csv-upload .summary-item"
+        return self._get_messages(title_css, detail_css)
+
+    def _get_messages(self, title_css, details_css):
+        """
+        Helper method to get messages given title and details CSS.
+        """
+        message_title = self.q(css=self._bounded_selector(title_css))
         if len(message_title.results) == 0:
             return []
         messages = [message_title.first.text[0]]
-        details = self.q(css="div.cohort-management-group-add .cohort-" + type + " .summary-item").results
+        details = self.q(css=self._bounded_selector(details_css)).results
         for detail in details:
             messages.append(detail.text)
         return messages
@@ -158,7 +232,20 @@ class MembershipPage(PageObject):
         """
         Click on the link to the Data Download Page.
         """
-        self.q(css="a.link-cross-reference[data-section=data_download]").first.click()
+        self.q(css=self._bounded_selector("a.link-cross-reference[data-section=data_download]")).first.click()
+
+    def upload_cohort_file(self, filename):
+        """
+        Uploads a file with cohort assignment information.
+        """
+        # If the CSV upload section has not yet been toggled on, click on the toggle link.
+        cvs_upload_toggle = self.q(css=self._bounded_selector(".toggle-cohort-management-secondary")).first
+        if cvs_upload_toggle:
+            cvs_upload_toggle.click()
+        path = InstructorDashboardPage.get_asset_path(filename)
+        file_input = self.q(css=self._bounded_selector(self.csv_browse_button_selector)).results[0]
+        file_input.send_keys(path)
+        self.q(css=self._bounded_selector(self.csv_upload_button_selector)).first.click()
 
 
 class MembershipPageAutoEnrollSection(PageObject):
@@ -215,49 +302,30 @@ class MembershipPageAutoEnrollSection(PageObject):
         self.wait_for_element_presence(error_message_selector, "%s message" % section_type.title())
         return self.q(css=error_message_selector).text[0]
 
-    def get_asset_path(self, file_name):
-        """
-        Returns the full path of the file to upload.
-        These files have been placed in edx-platform/common/test/data/uploads/
-        """
-
-        # Separate the list of folders in the path reaching to the current file,
-        # e.g.  '... common/test/acceptance/pages/lms/instructor_dashboard.py' will result in
-        #       [..., 'common', 'test', 'acceptance', 'pages', 'lms', 'instructor_dashboard.py']
-        folders_list_in_path = __file__.split(os.sep)
-
-        # Get rid of the last 4 elements: 'acceptance', 'pages', 'lms', and 'instructor_dashboard.py'
-        # to point to the 'test' folder, a shared point in the path's tree.
-        folders_list_in_path = folders_list_in_path[:-4]
-
-        # Append the folders in the asset's path
-        folders_list_in_path.extend(['data', 'uploads', file_name])
-
-        # Return the joined path of the required asset.
-        return os.sep.join(folders_list_in_path)
-
     def upload_correct_csv_file(self):
         """
         Selects the correct file and clicks the upload button.
         """
-        correct_files_path = self.get_asset_path('auto_reg_enrollment.csv')
-        self.q(css=self.auto_enroll_browse_button_selector).results[0].send_keys(correct_files_path)
-        self.click_upload_file_button()
+        self._upload_file('auto_reg_enrollment.csv')
 
     def upload_csv_file_with_errors_warnings(self):
         """
         Selects the file which will generate errors and warnings and clicks the upload button.
         """
-        errors_warnings_files_path = self.get_asset_path('auto_reg_enrollment_errors_warnings.csv')
-        self.q(css=self.auto_enroll_browse_button_selector).results[0].send_keys(errors_warnings_files_path)
-        self.click_upload_file_button()
+        self._upload_file('auto_reg_enrollment_errors_warnings.csv')
 
     def upload_non_csv_file(self):
         """
         Selects an image file and clicks the upload button.
         """
-        errors_warnings_files_path = self.get_asset_path('image.jpg')
-        self.q(css=self.auto_enroll_browse_button_selector).results[0].send_keys(errors_warnings_files_path)
+        self._upload_file('image.jpg')
+
+    def _upload_file(self, filename):
+        """
+        Helper method to upload a file with registration and enrollment information.
+        """
+        file_path = InstructorDashboardPage.get_asset_path(filename)
+        self.q(css=self.auto_enroll_browse_button_selector).results[0].send_keys(file_path)
         self.click_upload_file_button()
 
 
@@ -269,3 +337,10 @@ class DataDownloadPage(PageObject):
 
     def is_browser_on_page(self):
         return self.q(css='a[data-section=data_download].active-section').present
+
+    def get_available_reports_for_download(self):
+        """
+        Returns a list of all the available reports for download.
+        """
+        reports = self.q(css="#report-downloads-table .file-download-link>a").map(lambda el: el.text)
+        return reports.results
diff --git a/common/test/acceptance/tests/discussion/test_cohort_management.py b/common/test/acceptance/tests/discussion/test_cohort_management.py
index 146c9ee586..cf963e7f72 100644
--- a/common/test/acceptance/tests/discussion/test_cohort_management.py
+++ b/common/test/acceptance/tests/discussion/test_cohort_management.py
@@ -7,6 +7,7 @@ from datetime import datetime
 
 from pymongo import MongoClient
 
+from pytz import UTC, utc
 from bok_choy.promise import EmptyPromise
 from .helpers import CohortTestMixin
 from ..helpers import UniqueCourseTest
@@ -41,28 +42,37 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         # create a non-instructor who will be registered for the course and in the manual cohort.
         self.student_name = "student_user"
         self.student_id = AutoAuthPage(
-            self.browser, username=self.student_name, course_id=self.course_id, staff=False
+            self.browser, username=self.student_name, email="student_user@example.com",
+            course_id=self.course_id, staff=False
         ).visit().get_user_id()
         self.add_user_to_cohort(self.course_fixture, self.student_name, self.manual_cohort_id)
 
+        # create a user with unicode characters in their username
+        self.unicode_student_id = AutoAuthPage(
+            self.browser, username="Ωπ", email="unicode_student_user@example.com",
+            course_id=self.course_id, staff=False
+        ).visit().get_user_id()
+
         # login as an instructor
         self.instructor_name = "instructor_user"
         self.instructor_id = AutoAuthPage(
-            self.browser, username=self.instructor_name, course_id=self.course_id, staff=True
+            self.browser, username=self.instructor_name, email="instructor_user@example.com",
+            course_id=self.course_id, staff=True
         ).visit().get_user_id()
 
         # go to the membership page on the instructor dashboard
-        instructor_dashboard_page = InstructorDashboardPage(self.browser, self.course_id)
-        instructor_dashboard_page.visit()
-        self.membership_page = instructor_dashboard_page.select_membership()
+        self.instructor_dashboard_page = InstructorDashboardPage(self.browser, self.course_id)
+        self.instructor_dashboard_page.visit()
+        membership_page = self.instructor_dashboard_page.select_membership()
+        self.cohort_management_page = membership_page.select_cohort_management_section()
 
     def verify_cohort_description(self, cohort_name, expected_description):
         """
         Selects the cohort with the given name and verifies the expected description is presented.
         """
-        self.membership_page.select_cohort(cohort_name)
-        self.assertEquals(self.membership_page.get_selected_cohort(), cohort_name)
-        self.assertIn(expected_description, self.membership_page.get_cohort_group_setup())
+        self.cohort_management_page.select_cohort(cohort_name)
+        self.assertEquals(self.cohort_management_page.get_selected_cohort(), cohort_name)
+        self.assertIn(expected_description, self.cohort_management_page.get_cohort_group_setup())
 
     def test_cohort_description(self):
         """
@@ -93,8 +103,8 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         When I view the cohort in the LMS instructor dashboard
         There is a link to take me to the Studio Advanced Settings for the course
         """
-        self.membership_page.select_cohort(self.manual_cohort_name)
-        self.membership_page.select_edit_settings()
+        self.cohort_management_page.select_cohort(self.manual_cohort_name)
+        self.cohort_management_page.select_edit_settings()
         advanced_settings_page = AdvancedSettingsPage(
             self.browser, self.course_info['org'], self.course_info['number'], self.course_info['run']
         )
@@ -114,19 +124,19 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         And the user input field is empty
         And appropriate events have been emitted
         """
-        start_time = datetime.now()
-        self.membership_page.select_cohort(self.auto_cohort_name)
-        self.assertEqual(0, self.membership_page.get_selected_cohort_count())
-        self.membership_page.add_students_to_selected_cohort([self.student_name, self.instructor_name])
+        start_time = datetime.now(UTC)
+        self.cohort_management_page.select_cohort(self.auto_cohort_name)
+        self.assertEqual(0, self.cohort_management_page.get_selected_cohort_count())
+        self.cohort_management_page.add_students_to_selected_cohort([self.student_name, self.instructor_name])
         # Wait for the number of users in the cohort to change, indicating that the add operation is complete.
         EmptyPromise(
-            lambda: 2 == self.membership_page.get_selected_cohort_count(), 'Waiting for added students'
+            lambda: 2 == self.cohort_management_page.get_selected_cohort_count(), 'Waiting for added students'
         ).fulfill()
-        confirmation_messages = self.membership_page.get_cohort_confirmation_messages()
+        confirmation_messages = self.cohort_management_page.get_cohort_confirmation_messages()
         self.assertEqual(2, len(confirmation_messages))
         self.assertEqual("2 students have been added to this cohort group", confirmation_messages[0])
         self.assertEqual("1 student was removed from " + self.manual_cohort_name, confirmation_messages[1])
-        self.assertEqual("", self.membership_page.get_cohort_student_input_field_value())
+        self.assertEqual("", self.cohort_management_page.get_cohort_student_input_field_value())
         self.assertEqual(
             self.event_collection.find({
                 "name": "edx.cohort.user_added",
@@ -178,27 +188,27 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         And I get a notification that one user is unknown
         And the user input field still contains the incorrect email addresses
         """
-        self.membership_page.select_cohort(self.manual_cohort_name)
-        self.assertEqual(1, self.membership_page.get_selected_cohort_count())
-        self.membership_page.add_students_to_selected_cohort([self.student_name, "unknown_user"])
+        self.cohort_management_page.select_cohort(self.manual_cohort_name)
+        self.assertEqual(1, self.cohort_management_page.get_selected_cohort_count())
+        self.cohort_management_page.add_students_to_selected_cohort([self.student_name, "unknown_user"])
         # Wait for notification messages to appear, indicating that the add operation is complete.
         EmptyPromise(
-            lambda: 2 == len(self.membership_page.get_cohort_confirmation_messages()), 'Waiting for notification'
+            lambda: 2 == len(self.cohort_management_page.get_cohort_confirmation_messages()), 'Waiting for notification'
         ).fulfill()
-        self.assertEqual(1, self.membership_page.get_selected_cohort_count())
+        self.assertEqual(1, self.cohort_management_page.get_selected_cohort_count())
 
-        confirmation_messages = self.membership_page.get_cohort_confirmation_messages()
+        confirmation_messages = self.cohort_management_page.get_cohort_confirmation_messages()
         self.assertEqual(2, len(confirmation_messages))
         self.assertEqual("0 students have been added to this cohort group", confirmation_messages[0])
         self.assertEqual("1 student was already in the cohort group", confirmation_messages[1])
 
-        error_messages = self.membership_page.get_cohort_error_messages()
+        error_messages = self.cohort_management_page.get_cohort_error_messages()
         self.assertEqual(2, len(error_messages))
         self.assertEqual("There was an error when trying to add students:", error_messages[0])
         self.assertEqual("Unknown user: unknown_user", error_messages[1])
         self.assertEqual(
             self.student_name + ",unknown_user,",
-            self.membership_page.get_cohort_student_input_field_value()
+            self.cohort_management_page.get_cohort_student_input_field_value()
         )
 
     def test_add_new_cohort(self):
@@ -212,19 +222,19 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         Then the cohort has 1 user
         And appropriate events have been emitted
         """
-        start_time = datetime.now()
+        start_time = datetime.now(UTC)
         new_cohort = str(uuid.uuid4().get_hex()[0:20])
-        self.assertFalse(new_cohort in self.membership_page.get_cohorts())
-        self.membership_page.add_cohort(new_cohort)
+        self.assertFalse(new_cohort in self.cohort_management_page.get_cohorts())
+        self.cohort_management_page.add_cohort(new_cohort)
         # After adding the cohort, it should automatically be selected
         EmptyPromise(
-            lambda: new_cohort == self.membership_page.get_selected_cohort(), "Waiting for new cohort to appear"
+            lambda: new_cohort == self.cohort_management_page.get_selected_cohort(), "Waiting for new cohort to appear"
         ).fulfill()
-        self.assertEqual(0, self.membership_page.get_selected_cohort_count())
-        self.membership_page.add_students_to_selected_cohort([self.instructor_name])
+        self.assertEqual(0, self.cohort_management_page.get_selected_cohort_count())
+        self.cohort_management_page.add_students_to_selected_cohort([self.instructor_name])
         # Wait for the number of users in the cohort to change, indicating that the add operation is complete.
         EmptyPromise(
-            lambda: 1 == self.membership_page.get_selected_cohort_count(), 'Waiting for student to be added'
+            lambda: 1 == self.cohort_management_page.get_selected_cohort_count(), 'Waiting for student to be added'
         ).fulfill()
         self.assertEqual(
             self.event_collection.find({
@@ -252,6 +262,162 @@ class CohortConfigurationTest(UniqueCourseTest, CohortTestMixin):
         When I view the cohort in the LMS instructor dashboard
         There is a link to take me to the Data Download section of the Instructor Dashboard.
         """
-        self.membership_page.select_data_download()
+        self.cohort_management_page.select_data_download()
         data_download_page = DataDownloadPage(self.browser)
         data_download_page.wait_for_page()
+
+    def test_cohort_by_csv_both_columns(self):
+        """
+        Scenario: the instructor can upload a file with user and cohort assignments, using both emails and usernames.
+
+        Given I have a course with two cohorts defined
+        When I go to the cohort management section of the instructor dashboard
+        I can upload a CSV file with assignments of users to cohorts via both usernames and emails
+        Then I can download a file with results
+        And appropriate events have been emitted
+        """
+        # cohort_users_both_columns.csv adds instructor_user to ManualCohort1 via username and
+        # student_user to AutoCohort1 via email
+        self._verify_csv_upload_acceptable_file("cohort_users_both_columns.csv")
+
+    def test_cohort_by_csv_only_email(self):
+        """
+        Scenario: the instructor can upload a file with user and cohort assignments, using only emails.
+
+        Given I have a course with two cohorts defined
+        When I go to the cohort management section of the instructor dashboard
+        I can upload a CSV file with assignments of users to cohorts via only emails
+        Then I can download a file with results
+        And appropriate events have been emitted
+        """
+        # cohort_users_only_email.csv adds instructor_user to ManualCohort1 and student_user to AutoCohort1 via email
+        self._verify_csv_upload_acceptable_file("cohort_users_only_email.csv")
+
+    def test_cohort_by_csv_only_username(self):
+        """
+        Scenario: the instructor can upload a file with user and cohort assignments, using only usernames.
+
+        Given I have a course with two cohorts defined
+        When I go to the cohort management section of the instructor dashboard
+        I can upload a CSV file with assignments of users to cohorts via only usernames
+        Then I can download a file with results
+        And appropriate events have been emitted
+        """
+        # cohort_users_only_username.csv adds instructor_user to ManualCohort1 and
+        # student_user to AutoCohort1 via username
+        self._verify_csv_upload_acceptable_file("cohort_users_only_username.csv")
+
+    def _verify_csv_upload_acceptable_file(self, filename):
+        """
+        Helper method to verify cohort assignments after a successful CSV upload.
+        """
+        start_time = datetime.now(UTC)
+        self.cohort_management_page.upload_cohort_file(filename)
+        self._verify_cohort_by_csv_notification(
+            "Your file '{}' has been uploaded. Please allow a few minutes for processing.".format(filename)
+        )
+
+        # student_user is moved from manual cohort group to auto cohort group
+        self.assertEqual(
+            self.event_collection.find({
+                "name": "edx.cohort.user_added",
+                "time": {"$gt": start_time},
+                "event.user_id": {"$in": [int(self.student_id)]},
+                "event.cohort_name": self.auto_cohort_name,
+            }).count(),
+            1
+        )
+        self.assertEqual(
+            self.event_collection.find({
+                "name": "edx.cohort.user_removed",
+                "time": {"$gt": start_time},
+                "event.user_id": int(self.student_id),
+                "event.cohort_name": self.manual_cohort_name,
+            }).count(),
+            1
+        )
+        # instructor_user (previously unassigned) is added to manual cohort group
+        self.assertEqual(
+            self.event_collection.find({
+                "name": "edx.cohort.user_added",
+                "time": {"$gt": start_time},
+                "event.user_id": {"$in": [int(self.instructor_id)]},
+                "event.cohort_name": self.manual_cohort_name,
+            }).count(),
+            1
+        )
+        # unicode_student_user (previously unassigned) is added to manual cohort group
+        self.assertEqual(
+            self.event_collection.find({
+                "name": "edx.cohort.user_added",
+                "time": {"$gt": start_time},
+                "event.user_id": {"$in": [int(self.unicode_student_id)]},
+                "event.cohort_name": self.manual_cohort_name,
+            }).count(),
+            1
+        )
+
+        # Verify the results can be downloaded.
+        data_download = self.instructor_dashboard_page.select_data_download()
+        EmptyPromise(
+            lambda: 1 == len(data_download.get_available_reports_for_download()), 'Waiting for downloadable report'
+        ).fulfill()
+        report = data_download.get_available_reports_for_download()[0]
+        base_file_name = "cohort_results_"
+        self.assertIn("{}_{}".format(
+            '_'.join([self.course_info['org'], self.course_info['number'], self.course_info['run']]), base_file_name
+        ), report)
+        report_datetime = datetime.strptime(
+            report[report.index(base_file_name) + len(base_file_name):-len(".csv")],
+            "%Y-%m-%d-%H%M"
+        )
+        self.assertLessEqual(start_time.replace(second=0, microsecond=0), utc.localize(report_datetime))
+
+    def test_cohort_by_csv_wrong_file_type(self):
+        """
+        Scenario: if the instructor uploads a non-csv file, an error message is presented.
+
+        Given I have a course with cohorting enabled
+        When I go to the cohort management section of the instructor dashboard
+        And I upload a file without the CSV extension
+        Then I get an error message stating that the file must have a CSV extension
+        """
+        self.cohort_management_page.upload_cohort_file("image.jpg")
+        self._verify_cohort_by_csv_notification("The file must end with the extension '.csv'.")
+
+    def test_cohort_by_csv_missing_cohort(self):
+        """
+        Scenario: if the instructor uploads a csv file with no cohort column, an error message is presented.
+
+        Given I have a course with cohorting enabled
+        When I go to the cohort management section of the instructor dashboard
+        And I upload a CSV file that is missing the cohort column
+        Then I get an error message stating that the file must have a cohort column
+        """
+        self.cohort_management_page.upload_cohort_file("cohort_users_missing_cohort_column.csv")
+        self._verify_cohort_by_csv_notification("The file must contain a 'cohort' column containing cohort names.")
+
+    def test_cohort_by_csv_missing_user(self):
+        """
+        Scenario: if the instructor uploads a csv file with no username or email column, an error message is presented.
+
+        Given I have a course with cohorting enabled
+        When I go to the cohort management section of the instructor dashboard
+        And I upload a CSV file that is missing both the username and email columns
+        Then I get an error message stating that the file must have either a username or email column
+        """
+        self.cohort_management_page.upload_cohort_file("cohort_users_missing_user_columns.csv")
+        self._verify_cohort_by_csv_notification(
+            "The file must contain a 'username' column, an 'email' column, or both."
+        )
+
+    def _verify_cohort_by_csv_notification(self, expected_message):
+        """
+        Helper method to check the CSV file upload notification message.
+        """
+        # Wait for notification message to appear, indicating file has been uploaded.
+        EmptyPromise(
+            lambda: 1 == len(self.cohort_management_page.get_csv_messages()), 'Waiting for notification'
+        ).fulfill()
+        messages = self.cohort_management_page.get_csv_messages()
+        self.assertEquals(expected_message, messages[0])
diff --git a/common/test/acceptance/tests/lms/test_lms_staff_view.py b/common/test/acceptance/tests/lms/test_lms_staff_view.py
index 3d6bf77c09..12d0608eb0 100644
--- a/common/test/acceptance/tests/lms/test_lms_staff_view.py
+++ b/common/test/acceptance/tests/lms/test_lms_staff_view.py
@@ -107,10 +107,7 @@ class StaffDebugTest(UniqueCourseTest):
         staff_debug_page = staff_page.open_staff_debug_info()
         staff_debug_page.rescore()
         msg = staff_debug_page.idash_msg[0]
-        # Since we aren't running celery stuff, this will fail badly
-        # for now, but is worth excercising that bad of a response
-        self.assertEqual(u'Failed to rescore problem. '
-                         'Unknown Error Occurred.', msg)
+        self.assertEqual(u'Successfully rescored problem for user STAFF_TESTER', msg)
 
     def test_student_state_delete(self):
         """
@@ -176,10 +173,7 @@ class StaffDebugTest(UniqueCourseTest):
         staff_debug_page = staff_page.open_staff_debug_info()
         staff_debug_page.rescore()
         msg = staff_debug_page.idash_msg[0]
-        # Since we aren't running celery stuff, this will fail badly
-        # for now, but is worth excercising that bad of a response
-        self.assertEqual(u'Failed to rescore problem. '
-                         'Unknown Error Occurred.', msg)
+        self.assertEqual(u'Successfully rescored problem for user STAFF_TESTER', msg)
 
     def test_student_state_delete_for_problem_loaded_via_ajax(self):
         """
diff --git a/common/test/data/uploads/cohort_users_both_columns.csv b/common/test/data/uploads/cohort_users_both_columns.csv
new file mode 100644
index 0000000000..eced3db09d
--- /dev/null
+++ b/common/test/data/uploads/cohort_users_both_columns.csv
@@ -0,0 +1,4 @@
+username,email,ignored_column,cohort
+instructor_user,,June,ManualCohort1
+,student_user@example.com,Spring,AutoCohort1
+Ωπ,,Fall,ManualCohort1
diff --git a/common/test/data/uploads/cohort_users_missing_cohort_column.csv b/common/test/data/uploads/cohort_users_missing_cohort_column.csv
new file mode 100644
index 0000000000..01a8bb2237
--- /dev/null
+++ b/common/test/data/uploads/cohort_users_missing_cohort_column.csv
@@ -0,0 +1,3 @@
+username,email
+instructor_user,
+,student_user@example.com
diff --git a/common/test/data/uploads/cohort_users_missing_user_columns.csv b/common/test/data/uploads/cohort_users_missing_user_columns.csv
new file mode 100644
index 0000000000..e41a1b26aa
--- /dev/null
+++ b/common/test/data/uploads/cohort_users_missing_user_columns.csv
@@ -0,0 +1,3 @@
+cohort
+ManualCohort1
+AutoCohort1
diff --git a/common/test/data/uploads/cohort_users_only_email.csv b/common/test/data/uploads/cohort_users_only_email.csv
new file mode 100644
index 0000000000..7835d455fb
--- /dev/null
+++ b/common/test/data/uploads/cohort_users_only_email.csv
@@ -0,0 +1,5 @@
+email,cohort
+instructor_user@example.com,ManualCohort1
+student_user@example.com,AutoCohort1
+unicode_student_user@example.com,ManualCohort1
+
diff --git a/common/test/data/uploads/cohort_users_only_username.csv b/common/test/data/uploads/cohort_users_only_username.csv
new file mode 100644
index 0000000000..0c7588030a
--- /dev/null
+++ b/common/test/data/uploads/cohort_users_only_username.csv
@@ -0,0 +1,4 @@
+username,cohort
+instructor_user,ManualCohort1
+student_user,AutoCohort1
+Ωπ,ManualCohort1
\ No newline at end of file
diff --git a/lms/djangoapps/django_comment_client/base/views.py b/lms/djangoapps/django_comment_client/base/views.py
index 222754b9d7..c3db473e63 100644
--- a/lms/djangoapps/django_comment_client/base/views.py
+++ b/lms/djangoapps/django_comment_client/base/views.py
@@ -8,7 +8,6 @@ import urlparse
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth.models import User
 from django.core import exceptions
-from django.core.files.storage import get_storage_class
 from django.http import Http404, HttpResponseBadRequest
 from django.utils.translation import ugettext as _
 from django.views.decorators import csrf
@@ -17,6 +16,7 @@ from opaque_keys.edx.keys import CourseKey
 from opaque_keys.edx.locations import SlashSeparatedCourseKey
 
 from courseware.access import has_access
+from util.file import store_uploaded_file
 from courseware.courses import get_course_with_access, get_course_by_id
 import django_comment_client.settings as cc_settings
 from django_comment_client.utils import (
@@ -558,7 +558,6 @@ def upload(request, course_id):  # ajax upload file to a question or answer
     """
 
     # check upload permission
-    result = ''
     error = ''
     new_file_name = ''
     try:
@@ -570,29 +569,11 @@ def upload(request, course_id):  # ajax upload file to a question or answer
 
         #request.user.assert_can_upload_file()
 
-        # check file type
-        f = request.FILES['file-upload']
-        file_extension = os.path.splitext(f.name)[1].lower()
-        if not file_extension in cc_settings.ALLOWED_UPLOAD_FILE_TYPES:
-            file_types = "', '".join(cc_settings.ALLOWED_UPLOAD_FILE_TYPES)
-            msg = _("allowed file types are '%(file_types)s'") % \
-                {'file_types': file_types}
-            raise exceptions.PermissionDenied(msg)
-
-        # generate new file name
-        new_file_name = str(time.time()).replace('.', str(random.randint(0, 100000))) + file_extension
-
-        file_storage = get_storage_class()()
-        # use default storage to store file
-        file_storage.save(new_file_name, f)
-        # check file size
-        # byte
-        size = file_storage.size(new_file_name)
-        if size > cc_settings.MAX_UPLOAD_FILE_SIZE:
-            file_storage.delete(new_file_name)
-            msg = _("Maximum upload file size is %(file_size)s bytes.") % \
-                {'file_size': cc_settings.MAX_UPLOAD_FILE_SIZE}
-            raise exceptions.PermissionDenied(msg)
+        base_file_name = str(time.time()).replace('.', str(random.randint(0, 100000)))
+        file_storage, new_file_name = store_uploaded_file(
+            request, 'file-upload', cc_settings.ALLOWED_UPLOAD_FILE_TYPES, base_file_name,
+            max_file_size=cc_settings.MAX_UPLOAD_FILE_SIZE
+        )
 
     except exceptions.PermissionDenied, err:
         error = unicode(err)
diff --git a/lms/djangoapps/instructor/tests/test_api.py b/lms/djangoapps/instructor/tests/test_api.py
index aaf0f57f85..36ce43e068 100644
--- a/lms/djangoapps/instructor/tests/test_api.py
+++ b/lms/djangoapps/instructor/tests/test_api.py
@@ -6,8 +6,11 @@ import datetime
 import ddt
 import io
 import json
+import os
 import random
 import requests
+import shutil
+import tempfile
 from unittest import TestCase
 from urllib import quote
 
@@ -3289,3 +3292,166 @@ class TestCourseRegistrationCodes(ModuleStoreTestCase):
         self.assertEqual(response['Content-Type'], 'text/csv')
         body = response.content.replace('\r', '')
         self.assertTrue(body.startswith(EXPECTED_COUPON_CSV_HEADER))
+
+
+@override_settings(MODULESTORE=TEST_DATA_MOCK_MODULESTORE)
+class TestBulkCohorting(ModuleStoreTestCase):
+    """
+    Test adding users to cohorts in bulk via CSV upload.
+    """
+    def setUp(self):
+        super(TestBulkCohorting, self).setUp()
+        self.course = CourseFactory.create()
+        self.staff_user = StaffFactory(course_key=self.course.id)
+        self.non_staff_user = UserFactory.create()
+        self.tempdir = tempfile.mkdtemp()
+
+    def tearDown(self):
+        if os.path.exists(self.tempdir):
+            shutil.rmtree(self.tempdir)
+
+    def call_add_users_to_cohorts(self, csv_data, suffix='.csv', method='POST'):
+        """
+        Call `add_users_to_cohorts` with a file generated from `csv_data`.
+        """
+        # this temporary file will be removed in `self.tearDown()`
+        __, file_name = tempfile.mkstemp(suffix=suffix, dir=self.tempdir)
+        with open(file_name, 'w') as file_pointer:
+            file_pointer.write(csv_data.encode('utf-8'))
+        with open(file_name, 'r') as file_pointer:
+            url = reverse('add_users_to_cohorts', kwargs={'course_id': unicode(self.course.id)})
+            if method == 'POST':
+                return self.client.post(url, {'uploaded-file': file_pointer})
+            elif method == 'GET':
+                return self.client.get(url, {'uploaded-file': file_pointer})
+
+    def expect_error_on_file_content(self, file_content, error, file_suffix='.csv'):
+        """
+        Verify that we get the error we expect for a given file input.
+        """
+        self.client.login(username=self.staff_user.username, password='test')
+        response = self.call_add_users_to_cohorts(file_content, suffix=file_suffix)
+        self.assertEqual(response.status_code, 400)
+        result = json.loads(response.content)
+        self.assertEqual(result['error'], error)
+
+    def verify_success_on_file_content(self, file_content, mock_store_upload, mock_cohort_task):
+        """
+        Verify that `addd_users_to_cohorts` successfully validates the
+        file content, uploads the input file, and triggers the
+        background task.
+        """
+        mock_store_upload.return_value = (None, 'fake_file_name.csv')
+        self.client.login(username=self.staff_user.username, password='test')
+        response = self.call_add_users_to_cohorts(file_content)
+        self.assertEqual(response.status_code, 204)
+        self.assertTrue(mock_store_upload.called)
+        self.assertTrue(mock_cohort_task.called)
+
+    def test_no_cohort_field(self):
+        """
+        Verify that we get a descriptive verification error when we haven't
+        included a cohort field in the uploaded CSV.
+        """
+        self.expect_error_on_file_content(
+            'username,email\n', "The file must contain a 'cohort' column containing cohort names."
+        )
+
+    def test_no_username_or_email_field(self):
+        """
+        Verify that we get a descriptive verification error when we haven't
+        included a username or email field in the uploaded CSV.
+        """
+        self.expect_error_on_file_content(
+            'cohort\n', "The file must contain a 'username' column, an 'email' column, or both."
+        )
+
+    def test_empty_csv(self):
+        """
+        Verify that we get a descriptive verification error when we haven't
+        included any data in the uploaded CSV.
+        """
+        self.expect_error_on_file_content(
+            '', "The file must contain a 'cohort' column containing cohort names."
+        )
+
+    def test_wrong_extension(self):
+        """
+        Verify that we get a descriptive verification error when we haven't
+        uploaded a file with a '.csv' extension.
+        """
+        self.expect_error_on_file_content(
+            '', "The file must end with the extension '.csv'.", file_suffix='.notcsv'
+        )
+
+    def test_non_staff_no_access(self):
+        """
+        Verify that we can't access the view when we aren't a staff user.
+        """
+        self.client.login(username=self.non_staff_user.username, password='test')
+        response = self.call_add_users_to_cohorts('')
+        self.assertEqual(response.status_code, 403)
+
+    def test_post_only(self):
+        """
+        Verify that we can't call the view when we aren't using POST.
+        """
+        self.client.login(username=self.staff_user.username, password='test')
+        response = self.call_add_users_to_cohorts('', method='GET')
+        self.assertEqual(response.status_code, 405)
+
+    @patch('instructor.views.api.instructor_task.api.submit_cohort_students')
+    @patch('instructor.views.api.store_uploaded_file')
+    def test_success_username(self, mock_store_upload, mock_cohort_task):
+        """
+        Verify that we store the input CSV and call a background task when
+        the CSV has username and cohort columns.
+        """
+        self.verify_success_on_file_content(
+            'username,cohort\nfoo_username,bar_cohort', mock_store_upload, mock_cohort_task
+        )
+
+    @patch('instructor.views.api.instructor_task.api.submit_cohort_students')
+    @patch('instructor.views.api.store_uploaded_file')
+    def test_success_email(self, mock_store_upload, mock_cohort_task):
+        """
+        Verify that we store the input CSV and call the cohorting background
+        task when the CSV has email and cohort columns.
+        """
+        self.verify_success_on_file_content(
+            'email,cohort\nfoo_email,bar_cohort', mock_store_upload, mock_cohort_task
+        )
+
+    @patch('instructor.views.api.instructor_task.api.submit_cohort_students')
+    @patch('instructor.views.api.store_uploaded_file')
+    def test_success_username_and_email(self, mock_store_upload, mock_cohort_task):
+        """
+        Verify that we store the input CSV and call the cohorting background
+        task when the CSV has username, email and cohort columns.
+        """
+        self.verify_success_on_file_content(
+            'username,email,cohort\nfoo_username,bar_email,baz_cohort', mock_store_upload, mock_cohort_task
+        )
+
+    @patch('instructor.views.api.instructor_task.api.submit_cohort_students')
+    @patch('instructor.views.api.store_uploaded_file')
+    def test_success_carriage_return(self, mock_store_upload, mock_cohort_task):
+        """
+        Verify that we store the input CSV and call the cohorting background
+        task when lines in the CSV are delimited by carriage returns.
+        """
+        self.verify_success_on_file_content(
+            'username,email,cohort\rfoo_username,bar_email,baz_cohort', mock_store_upload, mock_cohort_task
+        )
+
+    @patch('instructor.views.api.instructor_task.api.submit_cohort_students')
+    @patch('instructor.views.api.store_uploaded_file')
+    def test_success_carriage_return_line_feed(self, mock_store_upload, mock_cohort_task):
+        """
+        Verify that we store the input CSV and call the cohorting background
+        task when lines in the CSV are delimited by carriage returns and line
+        feeds.
+        """
+        self.verify_success_on_file_content(
+            'username,email,cohort\r\nfoo_username,bar_email,baz_cohort', mock_store_upload, mock_cohort_task
+        )
diff --git a/lms/djangoapps/instructor/views/api.py b/lms/djangoapps/instructor/views/api.py
index a5efa2b738..45fce6b7f7 100644
--- a/lms/djangoapps/instructor/views/api.py
+++ b/lms/djangoapps/instructor/views/api.py
@@ -15,7 +15,7 @@ from django.conf import settings
 from django_future.csrf import ensure_csrf_cookie
 from django.views.decorators.http import require_POST
 from django.views.decorators.cache import cache_control
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ValidationError, PermissionDenied
 from django.core.mail.message import EmailMessage
 from django.db import IntegrityError
 from django.core.urlresolvers import reverse
@@ -25,7 +25,9 @@ from django.http import HttpResponse, HttpResponseBadRequest, HttpResponseForbid
 from django.utils.html import strip_tags
 import string  # pylint: disable=deprecated-module
 import random
+import unicodecsv
 import urllib
+from util.file import store_uploaded_file, course_and_time_based_filename_generator, FileValidationException, UniversalNewlineIterator
 from util.json_request import JsonResponse
 from instructor.views.instructor_task_helpers import extract_email_features, extract_task_features
 
@@ -956,6 +958,51 @@ def get_students_features(request, course_id, csv=False):  # pylint: disable=red
             return JsonResponse({"status": already_running_status})
 
 
+@ensure_csrf_cookie
+@cache_control(no_cache=True, no_store=True, must_revalidate=True)
+@require_POST
+@require_level('staff')
+def add_users_to_cohorts(request, course_id):
+    """
+    View method that accepts an uploaded file (using key "uploaded-file")
+    containing cohort assignments for users. This method spawns a celery task
+    to do the assignments, and a CSV file with results is provided via data downloads.
+    """
+    course_key = SlashSeparatedCourseKey.from_string(course_id)
+
+    try:
+        def validator(file_storage, file_to_validate):
+            """
+            Verifies that the expected columns are present.
+            """
+            with file_storage.open(file_to_validate) as f:
+                reader = unicodecsv.reader(UniversalNewlineIterator(f), encoding='utf-8')
+                try:
+                    fieldnames = next(reader)
+                except StopIteration:
+                    fieldnames = []
+                msg = None
+                if "cohort" not in fieldnames:
+                    msg = _("The file must contain a 'cohort' column containing cohort names.")
+                elif "email" not in fieldnames and "username" not in fieldnames:
+                    msg = _("The file must contain a 'username' column, an 'email' column, or both.")
+                if msg:
+                    raise FileValidationException(msg)
+
+        __, filename = store_uploaded_file(
+            request, 'uploaded-file', ['.csv'],
+            course_and_time_based_filename_generator(course_key, "cohorts"),
+            max_file_size=2000000,  # limit to 2 MB
+            validator=validator
+        )
+        # The task will assume the default file storage.
+        instructor_task.api.submit_cohort_students(request, course_key, filename)
+    except (FileValidationException, PermissionDenied) as err:
+        return JsonResponse({"error": unicode(err)}, status=400)
+
+    return JsonResponse()
+
+
 @ensure_csrf_cookie
 @cache_control(no_cache=True, no_store=True, must_revalidate=True)
 @require_level('staff')
diff --git a/lms/djangoapps/instructor/views/api_urls.py b/lms/djangoapps/instructor/views/api_urls.py
index e1d929fbcd..328190cdae 100644
--- a/lms/djangoapps/instructor/views/api_urls.py
+++ b/lms/djangoapps/instructor/views/api_urls.py
@@ -83,4 +83,8 @@ urlpatterns = patterns('',  # nopep8
     # spoc gradebook
     url(r'^gradebook$',
         'instructor.views.api.spoc_gradebook', name='spoc_gradebook'),
+
+    # Cohort management
+    url(r'add_users_to_cohorts$',
+        'instructor.views.api.add_users_to_cohorts', name="add_users_to_cohorts"),
 )
diff --git a/lms/djangoapps/instructor/views/instructor_dashboard.py b/lms/djangoapps/instructor/views/instructor_dashboard.py
index d12474fbf5..d6ccb40805 100644
--- a/lms/djangoapps/instructor/views/instructor_dashboard.py
+++ b/lms/djangoapps/instructor/views/instructor_dashboard.py
@@ -104,7 +104,7 @@ def instructor_dashboard_2(request, course_id):
 
     context = {
         'course': course,
-        'old_dashboard_url': reverse('instructor_dashboard_legacy', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'old_dashboard_url': reverse('instructor_dashboard_legacy', kwargs={'course_id': unicode(course_key)}),
         'studio_url': get_studio_url(course, 'course'),
         'sections': sections,
         'disable_buttons': disable_buttons,
@@ -141,23 +141,23 @@ def _section_e_commerce(course, access):
         'section_key': 'e-commerce',
         'section_display_name': _('E-Commerce'),
         'access': access,
-        'course_id': course_key.to_deprecated_string(),
+        'course_id': unicode(course_key),
         'currency_symbol': settings.PAID_COURSE_REGISTRATION_CURRENCY[1],
-        'ajax_remove_coupon_url': reverse('remove_coupon', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'ajax_get_coupon_info': reverse('get_coupon_info', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_user_invoice_preference_url': reverse('get_user_invoice_preference', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'sale_validation_url': reverse('sale_validation', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'ajax_update_coupon': reverse('update_coupon', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'ajax_add_coupon': reverse('add_coupon', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_sale_records_url': reverse('get_sale_records', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_sale_order_records_url': reverse('get_sale_order_records', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'instructor_url': reverse('instructor_dashboard', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_registration_code_csv_url': reverse('get_registration_codes', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'generate_registration_code_csv_url': reverse('generate_registration_codes', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'active_registration_code_csv_url': reverse('active_registration_codes', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'spent_registration_code_csv_url': reverse('spent_registration_codes', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'set_course_mode_url': reverse('set_course_mode_price', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'download_coupon_codes_url': reverse('get_coupon_codes', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'ajax_remove_coupon_url': reverse('remove_coupon', kwargs={'course_id': unicode(course_key)}),
+        'ajax_get_coupon_info': reverse('get_coupon_info', kwargs={'course_id': unicode(course_key)}),
+        'get_user_invoice_preference_url': reverse('get_user_invoice_preference', kwargs={'course_id': unicode(course_key)}),
+        'sale_validation_url': reverse('sale_validation', kwargs={'course_id': unicode(course_key)}),
+        'ajax_update_coupon': reverse('update_coupon', kwargs={'course_id': unicode(course_key)}),
+        'ajax_add_coupon': reverse('add_coupon', kwargs={'course_id': unicode(course_key)}),
+        'get_sale_records_url': reverse('get_sale_records', kwargs={'course_id': unicode(course_key)}),
+        'get_sale_order_records_url': reverse('get_sale_order_records', kwargs={'course_id': unicode(course_key)}),
+        'instructor_url': reverse('instructor_dashboard', kwargs={'course_id': unicode(course_key)}),
+        'get_registration_code_csv_url': reverse('get_registration_codes', kwargs={'course_id': unicode(course_key)}),
+        'generate_registration_code_csv_url': reverse('generate_registration_codes', kwargs={'course_id': unicode(course_key)}),
+        'active_registration_code_csv_url': reverse('active_registration_codes', kwargs={'course_id': unicode(course_key)}),
+        'spent_registration_code_csv_url': reverse('spent_registration_codes', kwargs={'course_id': unicode(course_key)}),
+        'set_course_mode_url': reverse('set_course_mode_price', kwargs={'course_id': unicode(course_key)}),
+        'download_coupon_codes_url': reverse('get_coupon_codes', kwargs={'course_id': unicode(course_key)}),
         'coupons': coupons,
         'course_price': course_price,
         'total_amount': total_amount
@@ -213,7 +213,7 @@ def _section_course_info(course, access):
         'course_display_name': course.display_name,
         'has_started': course.has_started(),
         'has_ended': course.has_ended(),
-        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': unicode(course_key)}),
     }
 
     if settings.FEATURES.get('DISPLAY_ANALYTICS_ENROLLMENTS'):
@@ -246,16 +246,17 @@ def _section_membership(course, access):
         'section_key': 'membership',
         'section_display_name': _('Membership'),
         'access': access,
-        'enroll_button_url': reverse('students_update_enrollment', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'unenroll_button_url': reverse('students_update_enrollment', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'upload_student_csv_button_url': reverse('register_and_enroll_students', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'modify_beta_testers_button_url': reverse('bulk_beta_modify_access', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'list_course_role_members_url': reverse('list_course_role_members', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'modify_access_url': reverse('modify_access', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'list_forum_members_url': reverse('list_forum_members', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'update_forum_role_membership_url': reverse('update_forum_role_membership', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'cohorts_ajax_url': reverse('cohorts', kwargs={'course_key_string': course_key.to_deprecated_string()}),
+        'enroll_button_url': reverse('students_update_enrollment', kwargs={'course_id': unicode(course_key)}),
+        'unenroll_button_url': reverse('students_update_enrollment', kwargs={'course_id': unicode(course_key)}),
+        'upload_student_csv_button_url': reverse('register_and_enroll_students', kwargs={'course_id': unicode(course_key)}),
+        'modify_beta_testers_button_url': reverse('bulk_beta_modify_access', kwargs={'course_id': unicode(course_key)}),
+        'list_course_role_members_url': reverse('list_course_role_members', kwargs={'course_id': unicode(course_key)}),
+        'modify_access_url': reverse('modify_access', kwargs={'course_id': unicode(course_key)}),
+        'list_forum_members_url': reverse('list_forum_members', kwargs={'course_id': unicode(course_key)}),
+        'update_forum_role_membership_url': reverse('update_forum_role_membership', kwargs={'course_id': unicode(course_key)}),
+        'cohorts_ajax_url': reverse('cohorts', kwargs={'course_key_string': unicode(course_key)}),
         'advanced_settings_url': get_studio_url(course, 'settings/advanced'),
+        'upload_cohorts_csv_url': reverse('add_users_to_cohorts', kwargs={'course_id': unicode(course_key)}),
     }
     return section_data
 
@@ -280,12 +281,12 @@ def _section_student_admin(course, access):
         'section_display_name': _('Student Admin'),
         'access': access,
         'is_small_course': is_small_course,
-        'get_student_progress_url_url': reverse('get_student_progress_url', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'enrollment_url': reverse('students_update_enrollment', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'reset_student_attempts_url': reverse('reset_student_attempts', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'rescore_problem_url': reverse('rescore_problem', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'spoc_gradebook_url': reverse('spoc_gradebook', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'get_student_progress_url_url': reverse('get_student_progress_url', kwargs={'course_id': unicode(course_key)}),
+        'enrollment_url': reverse('students_update_enrollment', kwargs={'course_id': unicode(course_key)}),
+        'reset_student_attempts_url': reverse('reset_student_attempts', kwargs={'course_id': unicode(course_key)}),
+        'rescore_problem_url': reverse('rescore_problem', kwargs={'course_id': unicode(course_key)}),
+        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': unicode(course_key)}),
+        'spoc_gradebook_url': reverse('spoc_gradebook', kwargs={'course_id': unicode(course_key)}),
     }
     return section_data
 
@@ -295,12 +296,12 @@ def _section_extensions(course):
     section_data = {
         'section_key': 'extensions',
         'section_display_name': _('Extensions'),
-        'units_with_due_dates': [(title_or_url(unit), unit.location.to_deprecated_string())
+        'units_with_due_dates': [(title_or_url(unit), unicode(unit.location))
                                  for unit in get_units_with_due_date(course)],
-        'change_due_date_url': reverse('change_due_date', kwargs={'course_id': course.id.to_deprecated_string()}),
-        'reset_due_date_url': reverse('reset_due_date', kwargs={'course_id': course.id.to_deprecated_string()}),
-        'show_unit_extensions_url': reverse('show_unit_extensions', kwargs={'course_id': course.id.to_deprecated_string()}),
-        'show_student_extensions_url': reverse('show_student_extensions', kwargs={'course_id': course.id.to_deprecated_string()}),
+        'change_due_date_url': reverse('change_due_date', kwargs={'course_id': unicode(course.id)}),
+        'reset_due_date_url': reverse('reset_due_date', kwargs={'course_id': unicode(course.id)}),
+        'show_unit_extensions_url': reverse('show_unit_extensions', kwargs={'course_id': unicode(course.id)}),
+        'show_student_extensions_url': reverse('show_student_extensions', kwargs={'course_id': unicode(course.id)}),
     }
     return section_data
 
@@ -312,12 +313,12 @@ def _section_data_download(course, access):
         'section_key': 'data_download',
         'section_display_name': _('Data Download'),
         'access': access,
-        'get_grading_config_url': reverse('get_grading_config', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_students_features_url': reverse('get_students_features', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'get_anon_ids_url': reverse('get_anon_ids', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'list_report_downloads_url': reverse('list_report_downloads', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'calculate_grades_csv_url': reverse('calculate_grades_csv', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'get_grading_config_url': reverse('get_grading_config', kwargs={'course_id': unicode(course_key)}),
+        'get_students_features_url': reverse('get_students_features', kwargs={'course_id': unicode(course_key)}),
+        'get_anon_ids_url': reverse('get_anon_ids', kwargs={'course_id': unicode(course_key)}),
+        'list_instructor_tasks_url': reverse('list_instructor_tasks', kwargs={'course_id': unicode(course_key)}),
+        'list_report_downloads_url': reverse('list_report_downloads', kwargs={'course_id': unicode(course_key)}),
+        'calculate_grades_csv_url': reverse('calculate_grades_csv', kwargs={'course_id': unicode(course_key)}),
     }
     return section_data
 
@@ -335,8 +336,8 @@ def _section_send_email(course, access):
     fragment = course.system.render(html_module, 'studio_view')
     fragment = wrap_xblock(
         'LmsRuntime', html_module, 'studio_view', fragment, None,
-        extra_data={"course-id": course_key.to_deprecated_string()},
-        usage_id_serializer=lambda usage_id: quote_slashes(usage_id.to_deprecated_string()),
+        extra_data={"course-id": unicode(course_key)},
+        usage_id_serializer=lambda usage_id: quote_slashes(unicode(usage_id)),
         # Generate a new request_token here at random, because this module isn't connected to any other
         # xblock rendering.
         request_token=uuid.uuid1().get_hex()
@@ -346,16 +347,16 @@ def _section_send_email(course, access):
         'section_key': 'send_email',
         'section_display_name': _('Email'),
         'access': access,
-        'send_email': reverse('send_email', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'send_email': reverse('send_email', kwargs={'course_id': unicode(course_key)}),
         'editor': email_editor,
         'list_instructor_tasks_url': reverse(
-            'list_instructor_tasks', kwargs={'course_id': course_key.to_deprecated_string()}
+            'list_instructor_tasks', kwargs={'course_id': unicode(course_key)}
         ),
         'email_background_tasks_url': reverse(
-            'list_background_email_tasks', kwargs={'course_id': course_key.to_deprecated_string()}
+            'list_background_email_tasks', kwargs={'course_id': unicode(course_key)}
         ),
         'email_content_history_url': reverse(
-            'list_email_content', kwargs={'course_id': course_key.to_deprecated_string()}
+            'list_email_content', kwargs={'course_id': unicode(course_key)}
         ),
     }
     return section_data
@@ -376,8 +377,8 @@ def _section_analytics(course, access):
         'section_key': 'instructor_analytics',
         'section_display_name': _('Analytics'),
         'access': access,
-        'get_distribution_url': reverse('get_distribution', kwargs={'course_id': course_key.to_deprecated_string()}),
-        'proxy_legacy_analytics_url': reverse('proxy_legacy_analytics', kwargs={'course_id': course_key.to_deprecated_string()}),
+        'get_distribution_url': reverse('get_distribution', kwargs={'course_id': unicode(course_key)}),
+        'proxy_legacy_analytics_url': reverse('proxy_legacy_analytics', kwargs={'course_id': unicode(course_key)}),
     }
 
     if settings.ANALYTICS_DASHBOARD_URL:
@@ -395,7 +396,7 @@ def _section_metrics(course, access):
         'section_key': 'metrics',
         'section_display_name': _('Metrics'),
         'access': access,
-        'course_id': course_key.to_deprecated_string(),
+        'course_id': unicode(course_key),
         'sub_section_display_name': get_section_display_name(course_key),
         'section_has_problem': get_array_section_has_problem(course_key),
         'get_students_opened_subsection_url': reverse('get_students_opened_subsection'),
diff --git a/lms/djangoapps/instructor_task/api.py b/lms/djangoapps/instructor_task/api.py
index 219df82899..5f18c86342 100644
--- a/lms/djangoapps/instructor_task/api.py
+++ b/lms/djangoapps/instructor_task/api.py
@@ -13,12 +13,15 @@ from celery.states import READY_STATES
 from xmodule.modulestore.django import modulestore
 
 from instructor_task.models import InstructorTask
-from instructor_task.tasks import (rescore_problem,
-                                   reset_problem_attempts,
-                                   delete_problem_state,
-                                   send_bulk_course_email,
-                                   calculate_grades_csv,
-                                   calculate_students_features_csv)
+from instructor_task.tasks import (
+    rescore_problem,
+    reset_problem_attempts,
+    delete_problem_state,
+    send_bulk_course_email,
+    calculate_grades_csv,
+    calculate_students_features_csv,
+    cohort_students,
+)
 
 from instructor_task.api_helper import (check_arguments_for_rescoring,
                                         encode_problem_and_student_input,
@@ -233,3 +236,17 @@ def submit_calculate_students_features_csv(request, course_key, features):
     task_key = ""
 
     return submit_task(request, task_type, task_class, course_key, task_input, task_key)
+
+
+def submit_cohort_students(request, course_key, file_name):
+    """
+    Request to have students cohorted in bulk.
+
+    Raises AlreadyRunningError if students are currently being cohorted.
+    """
+    task_type = 'cohort_students'
+    task_class = cohort_students
+    task_input = {'file_name': file_name}
+    task_key = ""
+
+    return submit_task(request, task_type, task_class, course_key, task_input, task_key)
diff --git a/lms/djangoapps/instructor_task/models.py b/lms/djangoapps/instructor_task/models.py
index e23f2ad1da..32415185fb 100644
--- a/lms/djangoapps/instructor_task/models.py
+++ b/lms/djangoapps/instructor_task/models.py
@@ -238,6 +238,7 @@ class S3ReportStore(ReportStore):
             settings.AWS_ACCESS_KEY_ID,
             settings.AWS_SECRET_ACCESS_KEY
         )
+
         self.bucket = conn.get_bucket(bucket_name)
 
     @classmethod
@@ -327,13 +328,10 @@ class S3ReportStore(ReportStore):
         can be plugged straight into an href
         """
         course_dir = self.key_for(course_id, '')
-        return sorted(
-            [
-                (key.key.split("/")[-1], key.generate_url(expires_in=300))
-                for key in self.bucket.list(prefix=course_dir.key)
-            ],
-            reverse=True
-        )
+        return [
+            (key.key.split("/")[-1], key.generate_url(expires_in=300))
+            for key in sorted(self.bucket.list(prefix=course_dir.key), reverse=True, key=lambda k: k.last_modified)
+        ]
 
 
 class LocalFSReportStore(ReportStore):
@@ -410,10 +408,10 @@ class LocalFSReportStore(ReportStore):
         course_dir = self.path_to(course_id, '')
         if not os.path.exists(course_dir):
             return []
-        return sorted(
-            [
-                (filename, ("file://" + urllib.quote(os.path.join(course_dir, filename))))
-                for filename in os.listdir(course_dir)
-            ],
-            reverse=True
-        )
+        files = [(filename, os.path.join(course_dir, filename)) for filename in os.listdir(course_dir)]
+        files.sort(key=lambda (filename, full_path): os.path.getmtime(full_path), reverse=True)
+
+        return [
+            (filename, ("file://" + urllib.quote(full_path)))
+            for filename, full_path in files
+        ]
diff --git a/lms/djangoapps/instructor_task/tasks.py b/lms/djangoapps/instructor_task/tasks.py
index 518d71da0a..76c8998090 100644
--- a/lms/djangoapps/instructor_task/tasks.py
+++ b/lms/djangoapps/instructor_task/tasks.py
@@ -31,7 +31,8 @@ from instructor_task.tasks_helper import (
     reset_attempts_module_state,
     delete_problem_module_state,
     upload_grades_csv,
-    upload_students_csv
+    upload_students_csv,
+    cohort_students_and_upload
 )
 from bulk_email.tasks import perform_delegate_email_batches
 
@@ -153,3 +154,15 @@ def calculate_students_features_csv(entry_id, xmodule_instance_args):
     action_name = ugettext_noop('generated')
     task_fn = partial(upload_students_csv, xmodule_instance_args)
     return run_main_task(entry_id, task_fn, action_name)
+
+
+@task(base=BaseInstructorTask)  # pylint: disable=E1102
+def cohort_students(entry_id, xmodule_instance_args):
+    """
+    Cohort students in bulk, and upload the results.
+    """
+    # Translators: This is a past-tense verb that is inserted into task progress messages as {action}.
+    # An example of such a message is: "Progress: {action} {succeeded} of {attempted} so far"
+    action_name = ugettext_noop('cohorted')
+    task_fn = partial(cohort_students_and_upload, xmodule_instance_args)
+    return run_main_task(entry_id, task_fn, action_name)
diff --git a/lms/djangoapps/instructor_task/tasks_helper.py b/lms/djangoapps/instructor_task/tasks_helper.py
index d712e824b2..70a5e2d42d 100644
--- a/lms/djangoapps/instructor_task/tasks_helper.py
+++ b/lms/djangoapps/instructor_task/tasks_helper.py
@@ -7,18 +7,23 @@ import json
 import urllib
 from datetime import datetime
 from time import time
+import unicodecsv
 
 from celery import Task, current_task
 from celery.utils.log import get_task_logger
 from celery.states import SUCCESS, FAILURE
 from django.contrib.auth.models import User
+from django.core.files.storage import DefaultStorage
 from django.db import transaction, reset_queries
 import dogstats_wrapper as dog_stats_api
 from pytz import UTC
 
-from xmodule.modulestore.django import modulestore
 from track.views import task_track
+from util.file import course_filename_prefix_generator, UniversalNewlineIterator
+from xmodule.modulestore.django import modulestore
 
+from openedx.core.djangoapps.course_groups.models import CourseUserGroup
+from openedx.core.djangoapps.course_groups.cohorts import add_user_to_cohort
 from courseware.grades import iterate_grades_for
 from courseware.models import StudentModule
 from courseware.model_data import FieldDataCache
@@ -515,7 +520,7 @@ def upload_csv_to_report_store(rows, csv_name, course_id, timestamp):
     report_store.store_rows(
         course_id,
         u"{course_prefix}_{csv_name}_{timestamp_str}.csv".format(
-            course_prefix=urllib.quote(unicode(course_id).replace("/", "_")),
+            course_prefix=course_filename_prefix_generator(course_id),
             csv_name=csv_name,
             timestamp_str=timestamp.strftime("%Y-%m-%d-%H%M")
         ),
@@ -624,3 +629,88 @@ def upload_students_csv(_xmodule_instance_args, _entry_id, course_id, task_input
     upload_csv_to_report_store(rows, 'student_profile_info', course_id, start_date)
 
     return task_progress.update_task_state(extra_meta=current_step)
+
+
+def cohort_students_and_upload(_xmodule_instance_args, _entry_id, course_id, task_input, action_name):
+    """
+    Within a given course, cohort students in bulk, then upload the results
+    using a `ReportStore`.
+    """
+    start_time = time()
+    start_date = datetime.now(UTC)
+
+    # Iterate through rows to get total assignments for task progress
+    with DefaultStorage().open(task_input['file_name']) as f:
+        total_assignments = 0
+        for _line in unicodecsv.DictReader(UniversalNewlineIterator(f)):
+            total_assignments += 1
+
+    task_progress = TaskProgress(action_name, total_assignments, start_time)
+    current_step = {'step': 'Cohorting Students'}
+    task_progress.update_task_state(extra_meta=current_step)
+
+    # cohorts_status is a mapping from cohort_name to metadata about
+    # that cohort.  The metadata will include information about users
+    # successfully added to the cohort, users not found, and a cached
+    # reference to the corresponding cohort object to prevent
+    # redundant cohort queries.
+    cohorts_status = {}
+
+    with DefaultStorage().open(task_input['file_name']) as f:
+        for row in unicodecsv.DictReader(UniversalNewlineIterator(f), encoding='utf-8'):
+            # Try to use the 'email' field to identify the user.  If it's not present, use 'username'.
+            username_or_email = row.get('email') or row.get('username')
+            cohort_name = row.get('cohort') or ''
+            task_progress.attempted += 1
+
+            if not cohorts_status.get(cohort_name):
+                cohorts_status[cohort_name] = {
+                    'Cohort Name': cohort_name,
+                    'Students Added': 0,
+                    'Students Not Found': set()
+                }
+                try:
+                    cohorts_status[cohort_name]['cohort'] = CourseUserGroup.objects.get(
+                        course_id=course_id,
+                        group_type=CourseUserGroup.COHORT,
+                        name=cohort_name
+                    )
+                    cohorts_status[cohort_name]["Exists"] = True
+                except CourseUserGroup.DoesNotExist:
+                    cohorts_status[cohort_name]["Exists"] = False
+
+            if not cohorts_status[cohort_name]['Exists']:
+                task_progress.failed += 1
+                continue
+
+            try:
+                with transaction.commit_on_success():
+                    add_user_to_cohort(cohorts_status[cohort_name]['cohort'], username_or_email)
+                cohorts_status[cohort_name]['Students Added'] += 1
+                task_progress.succeeded += 1
+            except User.DoesNotExist:
+                cohorts_status[cohort_name]['Students Not Found'].add(username_or_email)
+                task_progress.failed += 1
+            except ValueError:
+                # Raised when the user is already in the given cohort
+                task_progress.skipped += 1
+
+            task_progress.update_task_state(extra_meta=current_step)
+
+    current_step['step'] = 'Uploading CSV'
+    task_progress.update_task_state(extra_meta=current_step)
+
+    # Filter the output of `add_users_to_cohorts` in order to upload the result.
+    output_header = ['Cohort Name', 'Exists', 'Students Added', 'Students Not Found']
+    output_rows = [
+        [
+            ','.join(status_dict.get(column_name, '')) if column_name == 'Students Not Found'
+            else status_dict[column_name]
+            for column_name in output_header
+        ]
+        for _cohort_name, status_dict in cohorts_status.iteritems()
+    ]
+    output_rows.insert(0, output_header)
+    upload_csv_to_report_store(output_rows, 'cohort_results', course_id, start_date)
+
+    return task_progress.update_task_state(extra_meta=current_step)
diff --git a/lms/djangoapps/instructor_task/tests/test_api.py b/lms/djangoapps/instructor_task/tests/test_api.py
index 961c3b3dc0..81a63527d4 100644
--- a/lms/djangoapps/instructor_task/tests/test_api.py
+++ b/lms/djangoapps/instructor_task/tests/test_api.py
@@ -14,6 +14,7 @@ from instructor_task.api import (
     submit_delete_problem_state_for_all_students,
     submit_bulk_course_email,
     submit_calculate_students_features_csv,
+    submit_cohort_students,
 )
 
 from instructor_task.api_helper import AlreadyRunningError
@@ -201,3 +202,11 @@ class InstructorTaskCourseSubmitTest(TestReportMixin, InstructorTaskCourseTestCa
             features=[]
         )
         self._test_resubmission(api_call)
+
+    def test_submit_cohort_students(self):
+        api_call = lambda: submit_cohort_students(
+            self.create_task_request(self.instructor),
+            self.course.id,
+            file_name=u'filename.csv'
+        )
+        self._test_resubmission(api_call)
diff --git a/lms/djangoapps/instructor_task/tests/test_base.py b/lms/djangoapps/instructor_task/tests/test_base.py
index 1ce6eff9e8..bdc89cb0b8 100644
--- a/lms/djangoapps/instructor_task/tests/test_base.py
+++ b/lms/djangoapps/instructor_task/tests/test_base.py
@@ -6,6 +6,7 @@ import os
 import json
 from mock import Mock
 import shutil
+import unicodecsv
 from uuid import uuid4
 
 from celery.states import SUCCESS, FAILURE
@@ -26,7 +27,7 @@ from xmodule.modulestore.tests.factories import CourseFactory, ItemFactory
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 
 from instructor_task.api_helper import encode_problem_and_student_input
-from instructor_task.models import PROGRESS, QUEUING
+from instructor_task.models import PROGRESS, QUEUING, ReportStore
 from instructor_task.tests.factories import InstructorTaskFactory
 from instructor_task.views import instructor_task_status
 
@@ -246,3 +247,27 @@ class TestReportMixin(object):
         reports_download_path = settings.GRADES_DOWNLOAD['ROOT_PATH']
         if os.path.exists(reports_download_path):
             shutil.rmtree(reports_download_path)
+
+    def verify_rows_in_csv(self, expected_rows, verify_order=True):
+        """
+        Verify that the last ReportStore CSV contains the expected content.
+
+        Arguments:
+            expected_rows (iterable): An iterable of dictionaries,
+                where each dict represents a row of data in the last
+                ReportStore CSV.  Each dict maps keys from the CSV
+                header to values in that row's corresponding cell.
+            verify_order (boolean): When True, we verify that both the
+                content and order of `expected_rows` matches the
+                actual csv rows.  When False (default), we only verify
+                that the content matches.
+        """
+        report_store = ReportStore.from_config()
+        report_csv_filename = report_store.links_for(self.course.id)[0][0]
+        with open(report_store.path_to(self.course.id, report_csv_filename)) as csv_file:
+            # Expand the dict reader generator so we don't lose it's content
+            csv_rows = [row for row in unicodecsv.DictReader(csv_file)]
+            if verify_order:
+                self.assertEqual(csv_rows, expected_rows)
+            else:
+                self.assertItemsEqual(csv_rows, expected_rows)
diff --git a/lms/djangoapps/instructor_task/tests/test_integration.py b/lms/djangoapps/instructor_task/tests/test_integration.py
index eee8f124d3..68c1a44cbc 100644
--- a/lms/djangoapps/instructor_task/tests/test_integration.py
+++ b/lms/djangoapps/instructor_task/tests/test_integration.py
@@ -5,7 +5,6 @@ Runs tasks on answers to course problems to validate that code
 paths actually work.
 
 """
-import csv
 import json
 import logging
 from mock import patch
@@ -28,7 +27,7 @@ from instructor_task.api import (submit_rescore_problem_for_all_students,
                                  submit_rescore_problem_for_student,
                                  submit_reset_problem_attempts_for_all_students,
                                  submit_delete_problem_state_for_all_students)
-from instructor_task.models import InstructorTask, ReportStore
+from instructor_task.models import InstructorTask
 from instructor_task.tasks_helper import upload_grades_csv
 from instructor_task.tests.test_base import (InstructorTaskModuleTestCase, TestReportMixin, TEST_COURSE_ORG,
                                              TEST_COURSE_NUMBER, OPTION_1, OPTION_2)
@@ -602,23 +601,6 @@ class TestGradeReportConditionalContent(TestReportMixin, TestIntegrationTask):
         """
         self.assertDictContainsSubset({'attempted': 2, 'succeeded': 2, 'failed': 0}, task_result)
 
-    def verify_rows_in_csv(self, expected_rows):
-        """
-        Verify that the grades CSV contains the expected content.
-
-        Arguments:
-            expected_rows (iterable): An iterable of dictionaries, where
-                each dict represents a row of data in the grades
-                report CSV.  Each dict maps keys from the CSV header
-                to values in that row's corresponding cell.
-        """
-        report_store = ReportStore.from_config()
-        report_csv_filename = report_store.links_for(self.course.id)[0][0]
-        with open(report_store.path_to(self.course.id, report_csv_filename)) as csv_file:
-            # Expand the dict reader generator so we don't lose it's content
-            csv_rows = [row for row in csv.DictReader(csv_file)]
-            self.assertEqual(csv_rows, expected_rows)
-
     def verify_grades_in_csv(self, students_grades):
         """
         Verify that the grades CSV contains the expected grades data.
diff --git a/lms/djangoapps/instructor_task/tests/test_models.py b/lms/djangoapps/instructor_task/tests/test_models.py
new file mode 100644
index 0000000000..f681b71f85
--- /dev/null
+++ b/lms/djangoapps/instructor_task/tests/test_models.py
@@ -0,0 +1,107 @@
+"""
+Tests for instructor_task/models.py.
+"""
+
+from cStringIO import StringIO
+import mock
+import time
+from datetime import datetime
+from unittest import TestCase
+
+from instructor_task.models import LocalFSReportStore, S3ReportStore
+from instructor_task.tests.test_base import TestReportMixin
+from opaque_keys.edx.locator import CourseLocator
+
+
+class MockKey(object):
+    """
+    Mocking a boto S3 Key object.
+    """
+    def __init__(self, bucket):
+        self.last_modified = datetime.now()
+        self.bucket = bucket
+
+    def set_contents_from_string(self, contents, headers):  # pylint: disable=unused-argument
+        """ Expected method on a Key object. """
+        self.bucket.store_key(self)
+
+    def generate_url(self, expires_in):  # pylint: disable=unused-argument
+        """ Expected method on a Key object. """
+        return "http://fake-edx-s3.edx.org/"
+
+
+class MockBucket(object):
+    """ Mocking a boto S3 Bucket object. """
+    def __init__(self, _name):
+        self.keys = []
+
+    def store_key(self, key):
+        """ Not a Bucket method, created just to store the keys in the Bucket for testing purposes. """
+        self.keys.append(key)
+
+    def list(self, prefix):  # pylint: disable=unused-argument
+        """ Expected method on a Bucket object. """
+        return self.keys
+
+
+class MockS3Connection(object):
+    """ Mocking a boto S3 Connection """
+    def __init__(self, access_key, secret_key):
+        pass
+
+    def get_bucket(self, bucket_name):
+        """ Expected method on an S3Connection object. """
+        return MockBucket(bucket_name)
+
+
+class ReportStoreTestMixin(object):
+    """
+    Mixin for report store tests.
+    """
+    def setUp(self):
+        self.course_id = CourseLocator(org="testx", course="coursex", run="runx")
+
+    def create_report_store(self):
+        """
+        Subclasses should override this and return their report store.
+        """
+        pass
+
+    def test_links_for_order(self):
+        """
+        Test that ReportStore.links_for() returns file download links
+        in reverse chronological order.
+        """
+        report_store = self.create_report_store()
+        report_store.store(self.course_id, 'old_file', StringIO())
+        time.sleep(1)  # Ensure we have a unique timestamp.
+        report_store.store(self.course_id, 'middle_file', StringIO())
+        time.sleep(1)  # Ensure we have a unique timestamp.
+        report_store.store(self.course_id, 'new_file', StringIO())
+
+        self.assertEqual(
+            [link[0] for link in report_store.links_for(self.course_id)],
+            ['new_file', 'middle_file', 'old_file']
+        )
+
+
+class LocalFSReportStoreTestCase(ReportStoreTestMixin, TestReportMixin, TestCase):
+    """
+    Test the LocalFSReportStore model.
+    """
+    def create_report_store(self):
+        """ Create and return a LocalFSReportStore. """
+        return LocalFSReportStore.from_config()
+
+
+@mock.patch('instructor_task.models.S3Connection', new=MockS3Connection)
+@mock.patch('instructor_task.models.Key', new=MockKey)
+@mock.patch('instructor_task.models.settings.AWS_SECRET_ACCESS_KEY', create=True, new="access_key")
+@mock.patch('instructor_task.models.settings.AWS_ACCESS_KEY_ID', create=True, new="access_id")
+class S3ReportStoreTestCase(ReportStoreTestMixin, TestReportMixin, TestCase):
+    """
+    Test the S3ReportStore model.
+    """
+    def create_report_store(self):
+        """ Create and return a S3ReportStore. """
+        return S3ReportStore.from_config()
diff --git a/lms/djangoapps/instructor_task/tests/test_tasks_helper.py b/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
index 027e132cc9..7c324be9c8 100644
--- a/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
+++ b/lms/djangoapps/instructor_task/tests/test_tasks_helper.py
@@ -6,16 +6,13 @@ Tests that CSV grade report generation works with unicode emails.
 """
 import ddt
 from mock import Mock, patch
+import tempfile
 
-from django.test.testcases import TestCase
-
-from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
 
-from student.tests.factories import CourseEnrollmentFactory, UserFactory
-
+from openedx.core.djangoapps.course_groups.tests.helpers import CohortFactory
 from instructor_task.models import ReportStore
-from instructor_task.tasks_helper import upload_grades_csv, upload_students_csv
+from instructor_task.tasks_helper import cohort_students_and_upload, upload_grades_csv, upload_students_csv
 from instructor_task.tests.test_base import InstructorTaskCourseTestCase, TestReportMixin
 
 
@@ -104,3 +101,237 @@ class TestStudentReport(TestReportMixin, InstructorTaskCourseTestCase):
         #This assertion simply confirms that the generation completed with no errors
         num_students = len(students)
         self.assertDictContainsSubset({'attempted': num_students, 'succeeded': num_students, 'failed': 0}, result)
+
+
+class MockDefaultStorage(object):
+    """Mock django's DefaultStorage"""
+    def __init__(self):
+        pass
+
+    def open(self, file_name):
+        """Mock out DefaultStorage.open with standard python open"""
+        return open(file_name)
+
+
+@patch('instructor_task.tasks_helper.DefaultStorage', new=MockDefaultStorage)
+class TestCohortStudents(TestReportMixin, InstructorTaskCourseTestCase):
+    """
+    Tests that bulk student cohorting works.
+    """
+    def setUp(self):
+        self.course = CourseFactory.create()
+        self.cohort_1 = CohortFactory(course_id=self.course.id, name='Cohort 1')
+        self.cohort_2 = CohortFactory(course_id=self.course.id, name='Cohort 2')
+        self.student_1 = self.create_student(username=u'student_1\xec', email='student_1@example.com')
+        self.student_2 = self.create_student(username='student_2', email='student_2@example.com')
+        self.csv_header_row = ['Cohort Name', 'Exists', 'Students Added', 'Students Not Found']
+
+    def _cohort_students_and_upload(self, csv_data):
+        """
+        Call `cohort_students_and_upload` with a file generated from `csv_data`.
+        """
+        with tempfile.NamedTemporaryFile() as temp_file:
+            temp_file.write(csv_data.encode('utf-8'))
+            temp_file.flush()
+            with patch('instructor_task.tasks_helper._get_current_task'):
+                return cohort_students_and_upload(None, None, self.course.id, {'file_name': temp_file.name}, 'cohorted')
+
+    def test_username(self):
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,,Cohort 1\n'
+            u'student_2,,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_email(self):
+        result = self._cohort_students_and_upload(
+            'username,email,cohort\n'
+            ',student_1@example.com,Cohort 1\n'
+            ',student_2@example.com,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_username_and_email(self):
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,student_1@example.com,Cohort 1\n'
+            u'student_2,student_2@example.com,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_prefer_email(self):
+        """
+        Test that `cohort_students_and_upload` greedily prefers 'email' over
+        'username' when identifying the user.  This means that if a correct
+        email is present, an incorrect or non-matching username will simply be
+        ignored.
+        """
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,student_1@example.com,Cohort 1\n'  # valid username and email
+            u'Invalid,student_2@example.com,Cohort 2'      # invalid username, valid email
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_non_existent_user(self):
+        result = self._cohort_students_and_upload(
+            'username,email,cohort\n'
+            'Invalid,,Cohort 1\n'
+            'student_2,also_fake@bad.com,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 0, 'failed': 2}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '0', 'Invalid'])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '0', 'also_fake@bad.com'])),
+            ],
+            verify_order=False
+        )
+
+    def test_non_existent_cohort(self):
+        result = self._cohort_students_and_upload(
+            'username,email,cohort\n'
+            ',student_1@example.com,Does Not Exist\n'
+            'student_2,,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 1, 'failed': 1}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Does Not Exist', 'False', '0', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_too_few_commas(self):
+        """
+        A CSV file may be malformed and lack traling commas at the end of a row.
+        In this case, those cells take on the value None by the CSV parser.
+        Make sure we handle None values appropriately.
+
+        i.e.:
+            header_1,header_2,header_3
+            val_1,val_2,val_3  <- good row
+            val_1,,  <- good row
+            val_1    <- bad row; no trailing commas to indicate empty rows
+        """
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,\n'
+            u'student_2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 0, 'failed': 2}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['', 'False', '0', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_only_header_row(self):
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort'
+        )
+        self.assertDictContainsSubset({'total': 0, 'attempted': 0, 'succeeded': 0, 'failed': 0}, result)
+        self.verify_rows_in_csv([])
+
+    def test_carriage_return(self):
+        """
+        Test that we can handle carriage returns in our file.
+        """
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\r'
+            u'student_1\xec,,Cohort 1\r'
+            u'student_2,,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_carriage_return_line_feed(self):
+        """
+        Test that we can handle carriage returns and line feeds in our file.
+        """
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\r\n'
+            u'student_1\xec,,Cohort 1\r\n'
+            u'student_2,,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_move_users_to_new_cohort(self):
+        self.cohort_1.users.add(self.student_1)
+        self.cohort_2.users.add(self.student_2)
+
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,,Cohort 2\n'
+            u'student_2,,Cohort 1'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'succeeded': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '1', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '1', ''])),
+            ],
+            verify_order=False
+        )
+
+    def test_move_users_to_same_cohort(self):
+        self.cohort_1.users.add(self.student_1)
+        self.cohort_2.users.add(self.student_2)
+
+        result = self._cohort_students_and_upload(
+            u'username,email,cohort\n'
+            u'student_1\xec,,Cohort 1\n'
+            u'student_2,,Cohort 2'
+        )
+        self.assertDictContainsSubset({'total': 2, 'attempted': 2, 'skipped': 2, 'failed': 0}, result)
+        self.verify_rows_in_csv(
+            [
+                dict(zip(self.csv_header_row, ['Cohort 1', 'True', '0', ''])),
+                dict(zip(self.csv_header_row, ['Cohort 2', 'True', '0', ''])),
+            ],
+            verify_order=False
+        )
diff --git a/lms/envs/bok_choy.py b/lms/envs/bok_choy.py
index fbb2d6ef70..af3b992808 100644
--- a/lms/envs/bok_choy.py
+++ b/lms/envs/bok_choy.py
@@ -42,6 +42,17 @@ update_module_store_settings(
     default_store=os.environ.get('DEFAULT_STORE', 'draft'),
 )
 
+############################ STATIC FILES #############################
+DEFAULT_FILE_STORAGE = 'django.core.files.storage.FileSystemStorage'
+MEDIA_ROOT = TEST_ROOT / "uploads"
+MEDIA_URL = "/static/uploads/"
+
+################################# CELERY ######################################
+
+CELERY_ALWAYS_EAGER = True
+CELERY_RESULT_BACKEND = 'cache'
+BROKER_TRANSPORT = 'memory'
+
 ###################### Grade Downloads ######################
 GRADES_DOWNLOAD = {
     'STORAGE_TYPE': 'localfs',
diff --git a/lms/static/js/spec/main.js b/lms/static/js/spec/main.js
index d177124b9c..3242093e3d 100644
--- a/lms/static/js/spec/main.js
+++ b/lms/static/js/spec/main.js
@@ -60,6 +60,7 @@
             'js/staff_debug_actions': 'js/staff_debug_actions',
 
             // Backbone classes loaded explicitly until they are converted to use RequireJS
+            'js/views/file_uploader': 'js/views/file_uploader',
             'js/models/cohort': 'js/models/cohort',
             'js/collections/cohort': 'js/collections/cohort',
             'js/views/cohort_editor': 'js/views/cohort_editor',
@@ -82,7 +83,8 @@
                 exports: 'gettext'
             },
             'string_utils': {
-                deps: ['underscore']
+                deps: ['underscore'],
+                exports: 'interpolate_text'
             },
             'date': {
                 exports: 'Date'
@@ -283,7 +285,9 @@
             },
             'js/views/cohorts': {
                 exports: 'CohortsView',
-                deps: ['backbone', 'js/views/cohort_editor']
+                deps: ['jquery', 'underscore', 'backbone', 'gettext', 'string_utils', 'js/views/cohort_editor',
+                    'js/views/notification', 'js/models/notification', 'js/views/file_uploader'
+                ]
             },
             'js/models/notification': {
                 exports: 'NotificationModel',
@@ -293,6 +297,12 @@
                 exports: 'NotificationView',
                 deps: ['backbone', 'jquery', 'underscore']
             },
+            'js/views/file_uploader': {
+                exports: 'FileUploaderView',
+                deps: ['backbone', 'jquery', 'underscore', 'gettext', 'string_utils', 'js/views/notification',
+                    'js/models/notification', 'jquery.fileupload'
+                ]
+            },
             'js/student_account/enrollment': {
                 exports: 'edx.student.account.EnrollmentInterface',
                 deps: ['jquery', 'jquery.cookie']
@@ -385,6 +395,7 @@
         'lms/include/js/spec/photocapture_spec.js',
         'lms/include/js/spec/staff_debug_actions_spec.js',
         'lms/include/js/spec/views/notification_spec.js',
+        'lms/include/js/spec/views/file_uploader_spec.js',
         'lms/include/js/spec/dashboard/donation.js',
         'lms/include/js/spec/shoppingcart/shoppingcart_spec.js',
         'lms/include/js/spec/student_account/account_spec.js',
diff --git a/lms/static/js/spec/views/cohorts_spec.js b/lms/static/js/spec/views/cohorts_spec.js
index 0bf1a1a5d6..d3ff4cbfbb 100644
--- a/lms/static/js/spec/views/cohorts_spec.js
+++ b/lms/static/js/spec/views/cohorts_spec.js
@@ -28,7 +28,8 @@ define(['backbone', 'jquery', 'js/common_helpers/ajax_helpers', 'js/common_helpe
                 cohorts.url = '/mock_service';
                 requests = AjaxHelpers.requests(test);
                 cohortsView = new CohortsView({
-                    model: cohorts
+                    model: cohorts,
+                    upload_cohorts_csv_url: "http://upload-csv-file-url/"
                 });
                 cohortsView.render();
                 if (initialCohortID) {
@@ -91,12 +92,13 @@ define(['backbone', 'jquery', 'js/common_helpers/ajax_helpers', 'js/common_helpe
             };
 
             beforeEach(function () {
-                setFixtures("<div></div>");
+                setFixtures('<ul class="instructor-nav"><li class="nav-item"><<a href data-section="membership" class="active-section">Membership</a></li></ul><div></div>');
                 TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/cohorts');
                 TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/add-cohort-form');
                 TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/cohort-selector');
                 TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/cohort-editor');
                 TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/notification');
+                TemplateHelpers.installTemplate('templates/file-upload');
             });
 
             it("Show an error if no cohorts are defined", function() {
@@ -106,6 +108,18 @@ define(['backbone', 'jquery', 'js/common_helpers/ajax_helpers', 'js/common_helpe
                     'warning',
                     'Add Cohort Group'
                 );
+
+                // If no cohorts have been created, can't upload a CSV file.
+                expect(cohortsView.$('.wrapper-cohort-supplemental')).toHaveClass('is-hidden');
+            });
+
+            it("Syncs data when membership tab is clicked", function() {
+                createCohortsView(this, 1);
+                verifyHeader(1, 'Cat Lovers', catLoversInitialCount);
+                $(cohortsView.getSectionCss("membership")).click();
+                AjaxHelpers.expectRequest(requests, 'GET', '/mock_service');
+                respondToRefresh(1001, 2);
+                verifyHeader(1, 'Cat Lovers', 1001);
             });
 
             describe("Cohort Selector", function () {
@@ -115,6 +129,34 @@ define(['backbone', 'jquery', 'js/common_helpers/ajax_helpers', 'js/common_helpe
                     expect(cohortsView.$('.cohort-management-group-header .title-value').text()).toBe('');
                 });
 
+                it('can upload a CSV of cohort assignments if a cohort exists', function () {
+                    var uploadCsvToggle, fileUploadForm, fileUploadFormCss='#file-upload-form';
+
+                    createCohortsView(this);
+
+                    // Should see the control to toggle CSV file upload.
+                    expect(cohortsView.$('.wrapper-cohort-supplemental')).not.toHaveClass('is-hidden');
+                    // But upload form should not be visible until toggle is clicked.
+                    expect(cohortsView.$(fileUploadFormCss).length).toBe(0);
+                    uploadCsvToggle = cohortsView.$('.toggle-cohort-management-secondary');
+                    expect(uploadCsvToggle.text()).
+                        toContain('Assign students to cohort groups by uploading a CSV file');
+                    uploadCsvToggle.click();
+                    // After toggle is clicked, it should be hidden.
+                    expect(uploadCsvToggle).toHaveClass('is-hidden');
+
+                    fileUploadForm = cohortsView.$(fileUploadFormCss);
+                    expect(fileUploadForm.length).toBe(1);
+                    cohortsView.$(fileUploadForm).fileupload('add', {files: [{name: 'upload_file.txt'}]});
+                    cohortsView.$('.submit-file-button').click();
+
+                    // No file will actually be uploaded because "uploaded_file.txt" doesn't actually exist.
+                    AjaxHelpers.expectRequest(requests, 'POST', "http://upload-csv-file-url/", new FormData());
+                    AjaxHelpers.respondWithJson(requests, {});
+                    expect(cohortsView.$('.file-upload-form-result .message-confirmation .message-title').text().trim())
+                        .toBe("Your file 'upload_file.txt' has been uploaded. Please allow a few minutes for processing.");
+                });
+
                 it('can select a cohort', function () {
                     createCohortsView(this, 1);
                     verifyHeader(1, 'Cat Lovers', catLoversInitialCount);
diff --git a/lms/static/js/spec/views/file_uploader_spec.js b/lms/static/js/spec/views/file_uploader_spec.js
new file mode 100644
index 0000000000..d70c552ac4
--- /dev/null
+++ b/lms/static/js/spec/views/file_uploader_spec.js
@@ -0,0 +1,169 @@
+define(['backbone', 'jquery', 'js/views/file_uploader', 'js/common_helpers/template_helpers',
+        'js/common_helpers/ajax_helpers', 'js/models/notification', 'string_utils'],
+    function (Backbone, $, FileUploaderView, TemplateHelpers, AjaxHelpers, NotificationModel) {
+        describe("FileUploaderView", function () {
+            var verifyTitle, verifyInputLabel, verifyInputTip, verifySubmitButton, verifyExtensions, verifyText,
+                verifyFileUploadOption, verifyNotificationMessage, verifySubmitButtonEnabled, mimicUpload,
+                respondWithSuccess, respondWithError, fileUploaderView, url="http://test_url/";
+
+            verifyText = function (css, expectedText) {
+                expect(fileUploaderView.$(css).text().trim()).toBe(expectedText);
+            };
+
+            verifyTitle = function (expectedTitle) { verifyText('.form-title', expectedTitle); };
+
+            verifyInputLabel = function (expectedLabel) { verifyText('.field-label', expectedLabel); };
+
+            verifyInputTip = function (expectedTip) { verifyText('.tip', expectedTip); };
+
+            verifySubmitButton = function (expectedButton) { verifyText('.submit-file-button', expectedButton); };
+
+            verifyExtensions = function (expectedExtensions) {
+                var acceptAttribute = fileUploaderView.$('input.input-file').attr('accept');
+                if (expectedExtensions) {
+                    expect(acceptAttribute).toBe(expectedExtensions);
+                }
+                else {
+                    expect(acceptAttribute).toBe(undefined);
+                }
+            };
+
+            verifySubmitButtonEnabled = function (expectedEnabled) {
+                var submitButton = fileUploaderView.$('.submit-file-button');
+                if (expectedEnabled) {
+                    expect(submitButton).not.toHaveClass("is-disabled");
+                }
+                else {
+                    expect(submitButton).toHaveClass("is-disabled");
+                }
+            };
+
+            verifyFileUploadOption = function (option, expectedValue) {
+                expect(fileUploaderView.$('#file-upload-form').fileupload('option', option)).toBe(expectedValue);
+            };
+
+            verifyNotificationMessage = function (expectedMessage, type) {
+                verifyText('.file-upload-form-result .message-' + type + ' .message-title', expectedMessage);
+            };
+
+            mimicUpload = function (test) {
+                var requests = AjaxHelpers.requests(test);
+
+                var param = {files: [{name: 'upload_file.txt'}]};
+                fileUploaderView.$('#file-upload-form').fileupload('add', param);
+                verifySubmitButtonEnabled(true);
+                fileUploaderView.$('.submit-file-button').click();
+
+                // No file will actually be uploaded because "uploaded_file.txt" doesn't actually exist.
+                AjaxHelpers.expectRequest(requests, 'POST', url, new FormData());
+                return requests;
+            };
+
+            respondWithSuccess = function (requests) {
+                AjaxHelpers.respondWithJson(requests, {});
+            };
+
+            respondWithError = function (requests, errorMessage) {
+                if (errorMessage) {
+                    AjaxHelpers.respondWithError(requests, 500, {error: errorMessage});
+                }
+                else {
+                    AjaxHelpers.respondWithError(requests);
+                }
+            };
+
+            beforeEach(function () {
+                setFixtures("<div></div>");
+                TemplateHelpers.installTemplate('templates/file-upload');
+                TemplateHelpers.installTemplate('templates/instructor/instructor_dashboard_2/notification');
+                fileUploaderView = new FileUploaderView({url: url}).render();
+            });
+
+            it('has default values', function () {
+                verifyTitle("");
+                verifyInputLabel("");
+                verifyInputTip("");
+                verifySubmitButton("Upload File");
+                verifyExtensions(null);
+                verifySubmitButtonEnabled(false);
+            });
+
+            it ('can set text values and extensions', function () {
+                fileUploaderView = new FileUploaderView({
+                    title: "file upload title",
+                    inputLabel: "test label",
+                    inputTip: "test tip",
+                    submitButtonText: "upload button text",
+                    extensions: ".csv,.txt"
+                }).render();
+
+                verifyTitle("file upload title");
+                verifyInputLabel("test label");
+                verifyInputTip("test tip");
+                verifySubmitButton("upload button text");
+                verifyExtensions(".csv,.txt");
+            });
+
+            it ('can store upload URL', function () {
+                expect(fileUploaderView.$('#file-upload-form').attr('action')).toBe(url);
+            });
+
+            it ('sets autoUpload to false', function () {
+                verifyFileUploadOption('autoUpload', false);
+            });
+
+            it ('sets replaceFileInput to false', function () {
+                verifyFileUploadOption('replaceFileInput', false);
+            });
+
+            it ('handles errors with default message', function () {
+                var requests = mimicUpload(this);
+                respondWithError(requests);
+                verifyNotificationMessage("Your upload of 'upload_file.txt' failed.", "error");
+            });
+
+            it ('handles errors with custom message', function () {
+                fileUploaderView = new FileUploaderView({
+                    url: url,
+                    errorNotification: function (file, event, data) {
+                        var message = interpolate_text("Custom error for '{file}'", {file: file});
+                        return new NotificationModel({
+                            type: "customized",
+                            title: message
+                        });
+                    }
+                }).render();
+                var requests = mimicUpload(this);
+                respondWithError(requests, "server error");
+                verifyNotificationMessage("Custom error for 'upload_file.txt'", "customized");
+            });
+
+            it ('handles server error message', function () {
+                var requests = mimicUpload(this);
+                respondWithError(requests, "server error");
+                verifyNotificationMessage("server error", "error");
+            });
+
+            it ('handles success with default message', function () {
+                var requests = mimicUpload(this);
+                respondWithSuccess(requests);
+                verifyNotificationMessage("Your upload of 'upload_file.txt' succeeded.", "confirmation");
+            });
+
+            it ('handles success with custom message', function () {
+                fileUploaderView = new FileUploaderView({
+                    url: url,
+                    successNotification: function (file, event, data) {
+                        var message = interpolate_text("Custom success message for '{file}'", {file: file});
+                        return new NotificationModel({
+                            type: "customized",
+                            title: message
+                        });
+                    }
+                }).render();
+                var requests = mimicUpload(this);
+                respondWithSuccess(requests);
+                verifyNotificationMessage("Custom success message for 'upload_file.txt'", "customized");
+            });
+        });
+    });
diff --git a/lms/static/js/views/cohorts.js b/lms/static/js/views/cohorts.js
index 9f9131f316..7d1d9627a6 100644
--- a/lms/static/js/views/cohorts.js
+++ b/lms/static/js/views/cohorts.js
@@ -1,4 +1,4 @@
-(function($, _, Backbone, gettext, interpolate_text, CohortEditorView, NotificationModel, NotificationView) {
+(function($, _, Backbone, gettext, interpolate_text, CohortEditorView, NotificationModel, NotificationView, FileUploaderView) {
     var hiddenClass = 'is-hidden',
         disabledClass = 'is-disabled';
 
@@ -8,15 +8,26 @@
             'click .action-create': 'showAddCohortForm',
             'click .action-cancel': 'cancelAddCohortForm',
             'click .action-save': 'saveAddCohortForm',
-            'click .link-cross-reference': 'showSection'
+            'click .link-cross-reference': 'showSection',
+            'click .toggle-cohort-management-secondary': 'showCsvUpload'
         },
 
         initialize: function(options) {
+            var model = this.model;
+
             this.template = _.template($('#cohorts-tpl').text());
             this.selectorTemplate = _.template($('#cohort-selector-tpl').text());
             this.addCohortFormTemplate = _.template($('#add-cohort-form-tpl').text());
             this.advanced_settings_url = options.advanced_settings_url;
-            this.model.on('sync', this.onSync, this);
+            this.upload_cohorts_csv_url = options.upload_cohorts_csv_url;
+            model.on('sync', this.onSync, this);
+
+            // Update cohort counts when the user clicks back on the membership tab
+            // (for example, after uploading a csv file of cohort assignments and then
+            // checking results on data download tab).
+            $(this.getSectionCss('membership')).click(function () {
+                model.fetch();
+            });
         },
 
         render: function() {
@@ -36,16 +47,20 @@
 
         onSync: function() {
             var selectedCohort = this.lastSelectedCohortId && this.model.get(this.lastSelectedCohortId),
-                hasCohorts = this.model.length > 0;
+                hasCohorts = this.model.length > 0,
+                cohortNavElement = this.$('.cohort-management-nav'),
+                additionalCohortControlElement = this.$('.wrapper-cohort-supplemental');
             this.hideAddCohortForm();
             if (hasCohorts) {
-                this.$('.cohort-management-nav').removeClass(hiddenClass);
+                cohortNavElement.removeClass(hiddenClass);
+                additionalCohortControlElement.removeClass(hiddenClass);
                 this.renderSelector(selectedCohort);
                 if (selectedCohort) {
                     this.showCohortEditor(selectedCohort);
                 }
             } else {
-                this.$('.cohort-management-nav').addClass(hiddenClass);
+                cohortNavElement.addClass(hiddenClass);
+                additionalCohortControlElement.addClass(hiddenClass);
                 this.showNotification({
                     type: 'warning',
                     title: gettext('You currently have no cohort groups configured'),
@@ -176,8 +191,41 @@
         showSection: function(event) {
             event.preventDefault();
             var section = $(event.currentTarget).data("section");
-            $(".instructor-nav .nav-item a[data-section='" + section + "']").click();
+            $(this.getSectionCss(section)).click();
             $(window).scrollTop(0);
+        },
+
+        showCsvUpload: function(event) {
+            event.preventDefault();
+
+            $(event.currentTarget).addClass(hiddenClass);
+            var uploadElement = this.$('.csv-upload').removeClass(hiddenClass);
+
+            if (!this.fileUploaderView) {
+                this.fileUploaderView = new FileUploaderView({
+                    el: uploadElement,
+                    title: gettext("Assign students to cohort groups by uploading a CSV file."),
+                    inputLabel: gettext("Choose a .csv file"),
+                    inputTip: gettext("Only properly formatted .csv files will be accepted."),
+                    submitButtonText: gettext("Upload File and Assign Students"),
+                    extensions: ".csv",
+                    url: this.upload_cohorts_csv_url,
+                    successNotification: function (file, event, data) {
+                        var message = interpolate_text(gettext(
+                            "Your file '{file}' has been uploaded. Please allow a few minutes for processing."
+                        ), {file: file});
+                        return new NotificationModel({
+                            type: "confirmation",
+                            title: message
+                        });
+                    }
+                }).render();
+            }
+        },
+
+        getSectionCss: function (section) {
+            return ".instructor-nav .nav-item a[data-section='" + section + "']";
         }
+
     });
-}).call(this, $, _, Backbone, gettext, interpolate_text, CohortEditorView, NotificationModel, NotificationView);
+}).call(this, $, _, Backbone, gettext, interpolate_text, CohortEditorView, NotificationModel, NotificationView, FileUploaderView);
diff --git a/lms/static/js/views/file_uploader.js b/lms/static/js/views/file_uploader.js
new file mode 100644
index 0000000000..528c905176
--- /dev/null
+++ b/lms/static/js/views/file_uploader.js
@@ -0,0 +1,126 @@
+/**
+ * A view for uploading a file.
+ *
+ * Currently only single-file upload is supported (to support multiple-file uploads, the HTML
+ * input must be changed to specify "multiple" and the notification messaging needs to be changed
+ * to support the display of multiple status messages).
+ *
+ * There is no associated model, but the view supports the following options:
+ *
+ * @param title, the title to display.
+ * @param inputLabel, a label that will be added for the file input field. Note that this label is only shown to
+ *     screen readers.
+ * @param inputTip, a tooltip linked to the file input field. Can be used to state what sort of file can be uploaded.
+ * @param extensions, the allowed file extensions of the uploaded file, as a comma-separated string (ex, ".csv,.txt").
+ *     Some browsers will enforce that only files with these extensions can be uploaded, but others
+ *     (for instance, Firefox), will not. By default, no extensions are specified and any file can be uploaded.
+ * @param submitButtonText, text to display on the submit button to upload the file. The default value for this is
+ *     "Upload File".
+ * @param url, the url for posting the uploaded file.
+ * @param successNotification, optional callback that can return a success NotificationModel for display
+ *     after a file was successfully uploaded. This method will be passed the uploaded file, event, and data.
+ * @param errorNotification, optional callback that can return a success NotificationModel for display
+ *     after a file failed to upload. This method will be passed the attempted file, event, and data.
+ */
+(function (Backbone, $, _, gettext, interpolate_text, NotificationModel, NotificationView) {
+    // Requires JQuery-File-Upload.
+    var FileUploaderView = Backbone.View.extend({
+
+        initialize: function (options) {
+            this.template = _.template($('#file-upload-tpl').text());
+            this.options = options;
+        },
+
+        render: function () {
+            var options = this.options,
+                get_option_with_default = function(option, default_value) {
+                    var optionVal = options[option];
+                    return optionVal ? optionVal : default_value;
+                },
+                submitButton, resultNotification;
+
+            this.$el.html(this.template({
+                title: get_option_with_default("title", ""),
+                inputLabel: get_option_with_default("inputLabel", ""),
+                inputTip: get_option_with_default("inputTip", ""),
+                extensions: get_option_with_default("extensions", ""),
+                submitButtonText: get_option_with_default("submitButtonText", gettext("Upload File")),
+                url: get_option_with_default("url", "")
+            }));
+
+            submitButton = this.$el.find('.submit-file-button');
+            resultNotification = this.$el.find('.result'),
+
+            this.$el.find('#file-upload-form').fileupload({
+                dataType: 'json',
+                type: 'POST',
+                done: this.successHandler.bind(this),
+                fail: this.errorHandler.bind(this),
+                autoUpload: false,
+                replaceFileInput: false,
+                add: function (e, data) {
+                    var file = data.files[0];
+                    submitButton.removeClass("is-disabled");
+                    submitButton.unbind('click');
+                    submitButton.click(function (event) {
+                        event.preventDefault();
+                        data.submit();
+                    });
+                    resultNotification.html("");
+                }
+            });
+
+            return this;
+        },
+
+        successHandler: function (event, data) {
+            var file = data.files[0].name;
+            var notificationModel;
+            if (this.options.successNotification) {
+                notificationModel = this.options.successNotification(file, event, data);
+            }
+            else {
+                notificationModel = new NotificationModel({
+                    type: "confirmation",
+                    title: interpolate_text(gettext("Your upload of '{file}' succeeded."), {file: file})
+                });
+            }
+            var notification = new NotificationView({
+                el: this.$('.result'),
+                model: notificationModel
+            });
+            notification.render();
+        },
+
+        errorHandler: function (event, data) {
+            var file = data.files[0].name, message = null, jqXHR = data.response().jqXHR;
+            var notificationModel;
+            if (this.options.errorNotification) {
+                notificationModel = this.options.errorNotification(file, event, data);
+            }
+            else {
+                if (jqXHR.responseText) {
+                    try {
+                        message = JSON.parse(jqXHR.responseText).error;
+                    }
+                    catch (err) {
+                    }
+                }
+                if (!message) {
+                    message = interpolate_text(gettext("Your upload of '{file}' failed."), {file: file});
+                }
+                notificationModel = new NotificationModel({
+                    type: "error",
+                    title: message
+                });
+            }
+            var notification = new NotificationView({
+                el: this.$('.result'),
+                model: notificationModel
+            });
+            notification.render();
+        }
+    });
+
+    this.FileUploaderView = FileUploaderView;
+}).call(this, Backbone, $, _, gettext, interpolate_text, NotificationModel, NotificationView);
diff --git a/lms/static/js_test.yml b/lms/static/js_test.yml
index 10f140a9e3..410c92032c 100644
--- a/lms/static/js_test.yml
+++ b/lms/static/js_test.yml
@@ -41,6 +41,8 @@ lib_paths:
     - xmodule_js/common_static/js/vendor/flot/jquery.flot.js
     - xmodule_js/common_static/js/vendor/CodeMirror/codemirror.js
     - xmodule_js/common_static/js/vendor/URI.min.js
+    - xmodule_js/common_static/js/vendor/jQuery-File-Upload/js/jquery.fileupload.js
+    - xmodule_js/common_static/js/vendor/jQuery-File-Upload/js/jquery.iframe-transport.js
     - xmodule_js/common_static/js/vendor/url.min.js
     - xmodule_js/common_static/coffee/src/jquery.immediateDescendents.js
     - xmodule_js/common_static/coffee/src/xblock
@@ -76,6 +78,7 @@ fixture_paths:
     - templates/dashboard
     - templates/student_account
     - templates/student_profile
+    - templates/file-upload.underscore
 
 requirejs:
   paths:
diff --git a/lms/static/sass/course/instructor/_instructor_2.scss b/lms/static/sass/course/instructor/_instructor_2.scss
index dfff5cb518..67c7652f6b 100644
--- a/lms/static/sass/course/instructor/_instructor_2.scss
+++ b/lms/static/sass/course/instructor/_instructor_2.scss
@@ -106,6 +106,19 @@
       }
     }
   }
+
+  // UI: visual dividers
+  .divider-lv0 {
+    border-top: ($baseline/5) solid $gray-l4;
+  }
+
+  .divider-lv1 {
+    border-top: ($baseline/10) solid $gray-l4;
+  }
+
+  .divider-lv2 {
+    border-top: ($baseline/20) solid $gray-l4;
+  }
 }
 
 // instructor dashboard 2
@@ -311,6 +324,12 @@ section.instructor-dashboard-content-2 {
       color: $gray;
     }
   }
+
+  .subsection-title {
+    @extend %hd-lv5;
+    @extend %t-weight4;
+    margin-bottom: ($baseline/2);
+  }
 }
 
 
@@ -434,7 +453,7 @@ section.instructor-dashboard-content-2 {
       .tip {
         @extend %t-copy-sub1;
         margin-top: ($baseline/4);
-        color: $gray-l3;
+        color: $gray-l2;
       }
 
       .field-text {
@@ -449,6 +468,10 @@ section.instructor-dashboard-content-2 {
           padding: ($baseline/2) ($baseline*0.75);
         }
       }
+
+      .input-file {
+        margin-bottom: ($baseline/2);
+      }
     }
 
     .form-submit, .form-cancel {
@@ -472,7 +495,6 @@ section.instructor-dashboard-content-2 {
 
   .cohort-management-nav {
     @include clearfix();
-    margin-bottom: $baseline;
 
     .cohort-management-nav-form {
       width: 60%;
@@ -486,10 +508,10 @@ section.instructor-dashboard-content-2 {
 
     .action-create {
       @include idashbutton($blue);
+      @extend %t-weight4;
       float: right;
       text-align: right;
       text-shadow: none;
-      font-weight: 600;
     }
 
     // STATE: is disabled
@@ -538,10 +560,6 @@ section.instructor-dashboard-content-2 {
   }
 
   // cohort group
-  .cohort-management-group {
-    border: 1px solid $gray-l5;
-  }
-
   .cohort-management-group-header {
     border-bottom: ($baseline/10) solid $gray-l4;
     background: $gray-l5;
@@ -610,6 +628,7 @@ section.instructor-dashboard-content-2 {
 
   .cohort-management-group-add {
     @extend %cohort-management-form;
+    border: 1px solid $gray-l5;
     padding: $baseline $baseline 0 $baseline;
 
     .message-title {
@@ -646,10 +665,51 @@ section.instructor-dashboard-content-2 {
     }
   }
 
+  // CSV-based file upload for auto cohort assigning
+  .toggle-cohort-management-secondary {
+    @extend %t-copy-sub1;
+  }
+
+  .cohort-management-file-upload {
+
+    .message-title {
+      @extend %t-title7;
+    }
+
+    .form-introduction {
+      @extend %t-copy-sub1;
+      margin-bottom: $baseline;
+
+      p {
+        color: $gray-l1;
+      }
+    }
+  }
+
+  .file-upload-form {
+    @extend %cohort-management-form;
+
+    .form-fields {
+      margin-bottom: $baseline;
+    }
+
+    .action-submit {
+      @include idashbutton($blue);
+      // needed to override very poor specificity and base rules for blue button
+      @include font-size(14);
+      margin-bottom: 0;
+      font-weight: 700;
+      text-shadow: none;
+    }
+  }
 
   .cohort-management-supplemental {
     @extend %t-copy-sub1;
-    margin-top: ($baseline/2);
+    margin-top: $baseline;
+    padding: ($baseline/2) $baseline;
+    background: $gray-l5;
+    border-radius: ($baseline/10);
+
 
     .icon {
       margin-right: ($baseline/4);
diff --git a/lms/templates/file-upload.underscore b/lms/templates/file-upload.underscore
new file mode 100644
index 0000000000..5c9a99edfd
--- /dev/null
+++ b/lms/templates/file-upload.underscore
@@ -0,0 +1,24 @@
+<div class="wrapper-form">
+  <h3 class="form-title subsection-title"><%- title %></h3>
+
+  <div class="file-upload-form-result result"></div>
+
+  <form class="file-upload-form" id="file-upload-form" method="post" action="<%= url %>" enctype="multipart/form-data">
+
+      <div class="form-fields">
+        <div class="field field-file is-required">
+          <label class="field-label sr" for="file-upload-form-file"><%- inputLabel %></label>
+          <input id="file-upload-form-file" class="input input-file" name="uploaded-file" type="file"
+              <% if (extensions) { %>
+                  accept="<%- extensions %>"
+              <% } %>
+            />
+          <span class="tip tip-stacked"><%- inputTip %></span>
+        </div>
+      </div>
+
+      <div class="form-actions">
+        <button id="file-upload-form-submit" type="submit" class="submit-file-button action action-submit is-disabled"><%- submitButtonText %></button>
+      </div>
+  </form>
+</div>
diff --git a/lms/templates/instructor/instructor_dashboard_2/cohorts.underscore b/lms/templates/instructor/instructor_dashboard_2/cohorts.underscore
index 5c3e1710c5..db6fae6b5c 100644
--- a/lms/templates/instructor/instructor_dashboard_2/cohorts.underscore
+++ b/lms/templates/instructor/instructor_dashboard_2/cohorts.underscore
@@ -3,11 +3,12 @@
     <span class="description"></span>
 </h2>
 
-<!-- nav -->
 <div class="cohort-management-nav">
+    <h3 class="subsection-title"><%- gettext('Assign students to cohort groups manually') %></h3>
     <form action="" method="post" name="" id="cohort-management-nav-form" class="cohort-management-nav-form">
+
         <div class="cohort-management-nav-form-select field field-select">
-            <label for="cohort-select" class="label sr">${_("Select a cohort group to manage")}</label>
+            <label for="cohort-select" class="label sr"><%- gettext("Select a cohort group to manage") %></label>
             <select class="input cohort-select" name="cohort-select" id="cohort-select">
             </select>
         </div>
@@ -26,13 +27,22 @@
 <!-- individual group -->
 <div class="cohort-management-group"></div>
 
-<div class="cohort-management-supplemental">
-    <p class="">
-        <i class="icon icon-info-sign"></i>
-        <%= interpolate(
-        gettext('To review all student cohort group assignments, download course profile information on %(link_start)s the Data Download page. %(link_end)s'),
-            {link_start: '<a href="" class="link-cross-reference" data-section="data_download">', link_end: '</a>'},
-            true
-        ) %>
-    </p>
+<div class="wrapper-cohort-supplemental">
+
+    <hr class="divider divider-lv1" />
+
+    <!-- Uploading a CSV file of cohort assignments. -->
+    <a class="toggle-cohort-management-secondary" href="#cohort-management-file-upload"><%- gettext('Assign students to cohort groups by uploading a CSV file') %></a>
+    <div class="cohort-management-file-upload csv-upload is-hidden" id="cohort-management-file-upload"></div>
+
+    <div class="cohort-management-supplemental">
+        <p class="">
+            <i class="icon icon-info-sign"></i>
+            <%= interpolate(
+            gettext('To review student cohort group assignments or see the results of uploading a CSV file, download course profile information or cohort results on %(link_start)s the Data Download page. %(link_end)s'),
+                {link_start: '<a href="" class="link-cross-reference" data-section="data_download">', link_end: '</a>'},
+                true
+            ) %>
+        </p>
+    </div>
 </div>
diff --git a/lms/templates/instructor/instructor_dashboard_2/instructor_dashboard_2.html b/lms/templates/instructor/instructor_dashboard_2/instructor_dashboard_2.html
index 931f424b80..efee29766d 100644
--- a/lms/templates/instructor/instructor_dashboard_2/instructor_dashboard_2.html
+++ b/lms/templates/instructor/instructor_dashboard_2/instructor_dashboard_2.html
@@ -47,15 +47,17 @@
   <script type="text/javascript" src="${static.url('js/vendor/codemirror-compressed.js')}"></script>
   <script type="text/javascript" src="${static.url('js/vendor/tinymce/js/tinymce/tinymce.full.min.js')}"></script>
   <script type="text/javascript" src="${static.url('js/vendor/tinymce/js/tinymce/jquery.tinymce.min.js')}"></script>
+  <script type="text/javascript" src="${static.url('js/vendor/jQuery-File-Upload/js/jquery.fileupload.js')}"></script>
   <%static:js group='module-descriptor-js'/>
   <%static:js group='instructor_dash'/>
   <%static:js group='application'/>
 
   ## Backbone classes declared explicitly until RequireJS is supported
   <script type="text/javascript" src="${static.url('js/models/notification.js')}"></script>
+  <script type="text/javascript" src="${static.url('js/views/notification.js')}"></script>
+  <script type="text/javascript" src="${static.url('js/views/file_uploader.js')}"></script>
   <script type="text/javascript" src="${static.url('js/models/cohort.js')}"></script>
   <script type="text/javascript" src="${static.url('js/collections/cohort.js')}"></script>
-  <script type="text/javascript" src="${static.url('js/views/notification.js')}"></script>
   <script type="text/javascript" src="${static.url('js/views/cohort_editor.js')}"></script>
   <script type="text/javascript" src="${static.url('js/views/cohorts.js')}"></script>
 </%block>
@@ -67,6 +69,10 @@
   <%static:include path="instructor/instructor_dashboard_2/${template_name}.underscore" />
 </script>
 % endfor
+
+<script type="text/template" id="file-upload-tpl">
+  <%static:include path="file-upload.underscore" />
+</script>
 </%block>
 
 ## NOTE that instructor is set as the active page so that the instructor button lights up, even though this is the instructor_2 page.
diff --git a/lms/templates/instructor/instructor_dashboard_2/membership.html b/lms/templates/instructor/instructor_dashboard_2/membership.html
index 905ad0fe87..2d18373c37 100644
--- a/lms/templates/instructor/instructor_dashboard_2/membership.html
+++ b/lms/templates/instructor/instructor_dashboard_2/membership.html
@@ -249,6 +249,7 @@
     <div class="cohort-management membership-section"
          data-ajax_url="${section_data['cohorts_ajax_url']}"
          data-advanced-settings-url="${section_data['advanced_settings_url']}"
+         data-upload_cohorts_csv_url="${section_data['upload_cohorts_csv_url']}"
     >
     </div>
 
@@ -262,7 +263,8 @@
                 var cohortsView = new CohortsView({
                     el: cohortManagementElement,
                     model: cohorts,
-                    advanced_settings_url: cohortManagementElement.data('advanced-settings-url')
+                    advanced_settings_url: cohortManagementElement.data('advanced-settings-url'),
+                    upload_cohorts_csv_url: cohortManagementElement.data('upload_cohorts_csv_url')
                 });
                 cohorts.fetch().done(function() {
                     cohortsView.render();
diff --git a/openedx/core/djangoapps/course_groups/views.py b/openedx/core/djangoapps/course_groups/views.py
index fa92262486..37872e60bf 100644
--- a/openedx/core/djangoapps/course_groups/views.py
+++ b/openedx/core/djangoapps/course_groups/views.py
@@ -12,6 +12,7 @@ from opaque_keys.edx.locations import SlashSeparatedCourseKey
 from courseware.courses import get_course_with_access
 from edxmako.shortcuts import render_to_response
 
+from util.json_request import JsonResponse
 from . import cohorts
 from .models import CourseUserGroup
 
@@ -23,7 +24,7 @@ def json_http_response(data):
     Return an HttpResponse with the data json-serialized and the right content
     type header.
     """
-    return HttpResponse(json.dumps(data), content_type="application/json")
+    return JsonResponse(data)
 
 
 def split_by_comma_and_whitespace(cstr):
diff --git a/test_root/uploads/.git-keep b/test_root/uploads/.git-keep
deleted file mode 100644
index e69de29bb2..0000000000
diff --git a/test_root/uploads/.gitignore b/test_root/uploads/.gitignore
new file mode 100644
index 0000000000..afed0735dc
--- /dev/null
+++ b/test_root/uploads/.gitignore
@@ -0,0 +1 @@
+*.csv