diff --git a/.env b/.env
index 805961de..9fc7c719 100644
--- a/.env
+++ b/.env
@@ -14,6 +14,7 @@ LOGO_WHITE_URL=''
 FAVICON_URL=''
 MARKETING_SITE_BASE_URL=''
 ORDER_HISTORY_URL=''
+POST_MARK_AS_READ_DELAY=2000
 REFRESH_ACCESS_TOKEN_ENDPOINT=''
 SEGMENT_KEY=''
 SITE_NAME=''
diff --git a/.env.development b/.env.development
index 80f1b345..5266dd5d 100644
--- a/.env.development
+++ b/.env.development
@@ -15,6 +15,7 @@ LOGO_WHITE_URL=https://edx-cdn.org/v3/default/logo-white.svg
 FAVICON_URL=https://edx-cdn.org/v3/default/favicon.ico
 MARKETING_SITE_BASE_URL='http://localhost:18000'
 ORDER_HISTORY_URL='http://localhost:1996/orders'
+POST_MARK_AS_READ_DELAY=2000
 REFRESH_ACCESS_TOKEN_ENDPOINT='http://localhost:18000/login_refresh'
 SEGMENT_KEY=''
 SITE_NAME=localhost
diff --git a/.env.test b/.env.test
index 79c0f681..e6a9bc01 100644
--- a/.env.test
+++ b/.env.test
@@ -13,6 +13,7 @@ LOGO_WHITE_URL=https://edx-cdn.org/v3/default/logo-white.svg
 FAVICON_URL=https://edx-cdn.org/v3/default/favicon.ico
 MARKETING_SITE_BASE_URL='http://localhost:18000'
 ORDER_HISTORY_URL='http://localhost:1996/orders'
+POST_MARK_AS_READ_DELAY=2000
 REFRESH_ACCESS_TOKEN_ENDPOINT='http://localhost:18000/login_refresh'
 SEGMENT_KEY=''
 SITE_NAME=localhost
diff --git a/src/discussions/comments/CommentsView.jsx b/src/discussions/comments/CommentsView.jsx
index 4acacfe3..34993c2c 100644
--- a/src/discussions/comments/CommentsView.jsx
+++ b/src/discussions/comments/CommentsView.jsx
@@ -3,16 +3,20 @@ import React, { useEffect } from 'react';
 import { useDispatch, useSelector } from 'react-redux';
 import { useParams } from 'react-router';
 
+import { ensureConfig, getConfig } from '@edx/frontend-platform';
 import { injectIntl, intlShape } from '@edx/frontend-platform/i18n';
 import { Button, Spinner } from '@edx/paragon';
 
 import { selectThread } from '../posts/data/selectors';
+import { markThreadAsRead } from '../posts/data/thunks';
 import Post from '../posts/post/Post';
 import { selectThreadComments } from './data/selectors';
 import { fetchThreadComments } from './data/thunks';
 import Reply from './reply/Reply';
 import messages from './messages';
 
+ensureConfig(['POST_MARK_AS_READ_DELAY'], 'Comment thread view');
+
 function CommentsView({ intl }) {
   const { postId } = useParams();
   const dispatch = useDispatch();
@@ -20,6 +24,14 @@ function CommentsView({ intl }) {
   const comments = useSelector(selectThreadComments(postId));
   useEffect(() => {
     dispatch(fetchThreadComments(postId));
+    const markReadTimer = setTimeout(() => {
+      if (thread && !thread.read) {
+        dispatch(markThreadAsRead(postId));
+      }
+    }, getConfig().POST_MARK_AS_READ_DELAY);
+    return () => {
+      clearTimeout(markReadTimer);
+    };
   }, [postId]);
   if (!thread) {
     return (
diff --git a/src/discussions/posts/data/thunks.js b/src/discussions/posts/data/thunks.js
index 5a7db1c7..f17ac1c6 100644
--- a/src/discussions/posts/data/thunks.js
+++ b/src/discussions/posts/data/thunks.js
@@ -96,6 +96,23 @@ export function fetchThread(threadId) {
   };
 }
 
+export function markThreadAsRead(threadId) {
+  return async (dispatch) => {
+    try {
+      dispatch(updateThreadRequest({ threadId, read: true }));
+      const data = await updateThread(threadId, { read: true });
+      dispatch(updateThreadSuccess(camelCaseObject(data)));
+    } catch (error) {
+      if (getHttpErrorStatus(error) === 403) {
+        dispatch(updateThreadDenied());
+      } else {
+        dispatch(updateThreadFailed());
+      }
+      logError(error);
+    }
+  };
+}
+
 export function createNewThread(courseId, topicId, type, title, content, following = false) {
   return async (dispatch) => {
     try {
diff --git a/src/index.jsx b/src/index.jsx
index 50805cdc..10008c49 100755
--- a/src/index.jsx
+++ b/src/index.jsx
@@ -7,7 +7,7 @@ import ReactDOM from 'react-dom';
 import Footer, { messages as footerMessages } from '@edx/frontend-component-footer';
 import Header, { messages as headerMessages } from '@edx/frontend-component-header';
 import {
-  APP_INIT_ERROR, APP_READY, initialize, subscribe,
+  APP_INIT_ERROR, APP_READY, initialize, mergeConfig, subscribe,
 } from '@edx/frontend-platform';
 import { AppProvider, ErrorPage } from '@edx/frontend-platform/react';
 
@@ -40,4 +40,11 @@ initialize({
     headerMessages,
     footerMessages,
   ],
+  handlers: {
+    config() {
+      mergeConfig({
+        POST_MARK_AS_READ_DELAY: process.env.POST_MARK_AS_READ_DELAY || 2000,
+      });
+    },
+  },
 });