diff --git a/app/controllers/discussion_topics_controller.rb b/app/controllers/discussion_topics_controller.rb
index 93cb26ab31e..4db3ef15bee 100644
--- a/app/controllers/discussion_topics_controller.rb
+++ b/app/controllers/discussion_topics_controller.rb
@@ -793,7 +793,8 @@ class DiscussionTopicsController < ApplicationController
                # GRADED_RUBRICS_URL must be within DISCUSSION to avoid page error
                DISCUSSION: {
                  GRADED_RUBRICS_URL: (@topic.assignment ? context_url(@topic.assignment.context, :context_assignment_rubric_url, @topic.assignment.id) : nil),
-                 CONTEXT_RUBRICS_URL: can_do(@topic.assignment, @current_user, :update) ? context_url(@topic.assignment.context, :context_rubrics_url) : ""
+                 CONTEXT_RUBRICS_URL: can_do(@topic.assignment, @current_user, :update) ? context_url(@topic.assignment.context, :context_rubrics_url) : "",
+                 ATTACHMENTS_FOLDER_ID: (@topic.for_assignment? && !@current_user.nil?) ? @current_user.submissions_folder(@context).id : Folder.unfiled_folder(@context).id
                },
                apollo_caching: @current_user &&
                  Account.site_admin.feature_enabled?(:apollo_caching),
diff --git a/spec/controllers/discussion_topics_controller_spec.rb b/spec/controllers/discussion_topics_controller_spec.rb
index e84f80c981e..5ff2d78f909 100644
--- a/spec/controllers/discussion_topics_controller_spec.rb
+++ b/spec/controllers/discussion_topics_controller_spec.rb
@@ -551,6 +551,46 @@ describe DiscussionTopicsController do
         user_session(user)
       end
 
+      it "sets ATTACHMENTS_FOLDER_ID" do
+        subject
+
+        expect(discussion).not_to be_for_assignment
+        expect(assigns[:js_env][:DISCUSSION][:ATTACHMENTS_FOLDER_ID]).to eq Folder.unfiled_folder(discussion.course).id.to_s
+      end
+
+      context "no current user" do
+        it "public course sets ATTACHMENTS_FOLDER_ID" do
+          Account.default.enable_feature! :react_discussions_post
+          # in the controller 'can_read_and_visible' must be true, which is a complex flow to simulate
+          allow_any_instance_of(DiscussionTopic).to receive(:grants_right?).and_return(true)
+          allow_any_instance_of(DiscussionTopic).to receive(:visible_for?).and_return(true)
+
+          course.update(is_public: true)
+          discussion.assignment = course.assignments.build(submission_types: "discussion_topic", title: discussion.title)
+          discussion.assignment.infer_times
+          discussion.assignment.saved_by = :discussion_topic
+          discussion.save
+          remove_user_session
+
+          subject
+          expect(discussion).to be_for_assignment
+          expect(assigns[:js_env][:DISCUSSION][:ATTACHMENTS_FOLDER_ID]).to eq Folder.unfiled_folder(discussion.course).id.to_s
+        end
+      end
+
+      context "for_assignment" do
+        it "sets ATTACHMENTS_FOLDER_ID" do
+          discussion.assignment = course.assignments.build(submission_types: "discussion_topic", title: discussion.title)
+          discussion.assignment.infer_times
+          discussion.assignment.saved_by = :discussion_topic
+          discussion.save
+
+          subject
+          expect(discussion).to be_for_assignment
+          expect(assigns[:js_env][:DISCUSSION][:ATTACHMENTS_FOLDER_ID]).to eq user.submissions_folder(discussion.course).id.to_s
+        end
+      end
+
       it "sets @page_title to Topic: @topic.title" do
         subject
         expect(assigns(:page_title)).to eq "Topic: #{discussion.title}"
diff --git a/ui/features/discussion_topics_post/graphql/Mocks.js b/ui/features/discussion_topics_post/graphql/Mocks.js
index eed3a1b0685..6bc0feae563 100644
--- a/ui/features/discussion_topics_post/graphql/Mocks.js
+++ b/ui/features/discussion_topics_post/graphql/Mocks.js
@@ -353,7 +353,8 @@ export const updateDiscussionEntryParticipantMock = ({
 export const updateDiscussionEntryMock = ({
   discussionEntryId = 'DiscussionEntry-default-mock',
   message = '<p>This is the parent reply</p>',
-  removeAttachment = !'7',
+  fileId = '7',
+  removeAttachment = !fileId,
 } = {}) => [
   {
     request: {
@@ -361,6 +362,7 @@ export const updateDiscussionEntryMock = ({
       variables: {
         discussionEntryId,
         message,
+        ...(fileId !== null && {fileId}),
         removeAttachment,
       },
     },
@@ -413,6 +415,7 @@ export const createDiscussionEntryMock = ({
   discussionTopicId = 'Discussion-default-mock',
   message = '',
   replyFromEntryId = null,
+  fileId = null,
   includeReplyPreview = null,
   isAnonymousAuthor = false,
   courseID = '1',
@@ -425,6 +428,7 @@ export const createDiscussionEntryMock = ({
         message,
         isAnonymousAuthor,
         ...(replyFromEntryId !== null && {replyFromEntryId}),
+        ...(fileId !== null && {fileId}),
         ...(includeReplyPreview !== null && {includeReplyPreview}),
         ...(courseID !== null && {courseID}),
       },
diff --git a/ui/features/discussion_topics_post/graphql/Mutations.js b/ui/features/discussion_topics_post/graphql/Mutations.js
index 7856b982d5f..848347f2ee2 100644
--- a/ui/features/discussion_topics_post/graphql/Mutations.js
+++ b/ui/features/discussion_topics_post/graphql/Mutations.js
@@ -132,6 +132,7 @@ export const CREATE_DISCUSSION_ENTRY = gql`
     $discussionTopicId: ID!
     $message: String!
     $replyFromEntryId: ID
+    $fileId: ID
     $includeReplyPreview: Boolean
     $isAnonymousAuthor: Boolean
     $courseID: String
@@ -141,6 +142,7 @@ export const CREATE_DISCUSSION_ENTRY = gql`
         discussionTopicId: $discussionTopicId
         message: $message
         parentEntryId: $replyFromEntryId
+        fileId: $fileId
         includeReplyPreview: $includeReplyPreview
         isAnonymousAuthor: $isAnonymousAuthor
       }
@@ -172,12 +174,14 @@ export const UPDATE_DISCUSSION_ENTRY = gql`
   mutation UpdateDiscussionEntry(
     $discussionEntryId: ID!
     $message: String
+    $fileId: ID
     $removeAttachment: Boolean
   ) {
     updateDiscussionEntry(
       input: {
         discussionEntryId: $discussionEntryId
         message: $message
+        fileId: $fileId
         removeAttachment: $removeAttachment
       }
     ) {
diff --git a/ui/features/discussion_topics_post/react/DiscussionTopicManager.js b/ui/features/discussion_topics_post/react/DiscussionTopicManager.js
index 0ac5fbe2392..74e37e20e69 100644
--- a/ui/features/discussion_topics_post/react/DiscussionTopicManager.js
+++ b/ui/features/discussion_topics_post/react/DiscussionTopicManager.js
@@ -306,11 +306,12 @@ const DiscussionTopicManager = props => {
             <DiscussionTopicContainer
               updateDraftCache={updateDraftCache}
               discussionTopic={discussionTopicQuery.data.legacyNode}
-              createDiscussionEntry={(message, isAnonymousAuthor) => {
+              createDiscussionEntry={(message, fileId, isAnonymousAuthor) => {
                 createDiscussionEntry({
                   variables: {
                     discussionTopicId: ENV.discussion_topic_id,
                     message,
+                    fileId,
                     courseID: ENV.course_id,
                     isAnonymousAuthor,
                   },
diff --git a/ui/features/discussion_topics_post/react/__tests__/DiscussionsAttachment.test.js b/ui/features/discussion_topics_post/react/__tests__/DiscussionsAttachment.test.js
index d64b051181f..b04d2b60899 100644
--- a/ui/features/discussion_topics_post/react/__tests__/DiscussionsAttachment.test.js
+++ b/ui/features/discussion_topics_post/react/__tests__/DiscussionsAttachment.test.js
@@ -33,7 +33,7 @@ jest.mock('../utils', () => ({
   responsiveQuerySizes: jest.fn(),
 }))
 
-describe('DiscussionThreadAttachment', () => {
+describe('DiscussionsAttachment', () => {
   const onFailureStub = jest.fn()
   const onSuccessStub = jest.fn()
   const openMock = jest.fn()
@@ -90,6 +90,7 @@ describe('DiscussionThreadAttachment', () => {
         updateDiscussionEntryMock({
           discussionEntryId: 'DiscussionEntry-default-mock',
           message: '<p>This is the parent reply</p>',
+          fileId: null,
           removeAttachment: true,
         })
       )
diff --git a/ui/features/discussion_topics_post/react/components/AttachmentDisplay/AttachmentDisplay.js b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/AttachmentDisplay.js
index 338dbfa3fb6..c9dba2edcb6 100644
--- a/ui/features/discussion_topics_post/react/components/AttachmentDisplay/AttachmentDisplay.js
+++ b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/AttachmentDisplay.js
@@ -17,17 +17,55 @@
  */
 
 import PropTypes from 'prop-types'
-import React from 'react'
+import React, {useContext} from 'react'
 import {AttachmentButton} from './AttachmentButton'
-
+import {AlertManagerContext} from '@canvas/alerts/react/AlertManager'
 import {Responsive} from '@instructure/ui-responsive'
 import {responsiveQuerySizes} from '../../utils'
+import {UploadButton} from './UploadButton'
+import {uploadFiles} from '@canvas/upload-file'
+import {useScope as useI18nScope} from '@canvas/i18n'
 
+const I18n = useI18nScope('discussion_topics_post')
 export function AttachmentDisplay(props) {
+  const {setOnFailure, setOnSuccess} = useContext(AlertManagerContext)
+
   const removeAttachment = () => {
     props.setAttachment(null)
   }
 
+  const fileUploadUrl = attachmentFolderId => {
+    return `/api/v1/folders/${attachmentFolderId}/files`
+  }
+
+  const addAttachment = async e => {
+    const files = Array.from(e.currentTarget?.files)
+    if (files.length !== 1) {
+      setOnFailure(I18n.t('Error adding file to discussion message'))
+    }
+
+    props.setAttachmentToUpload(true)
+
+    setOnSuccess(I18n.t('Uploading file'))
+
+    try {
+      const newFiles = await uploadFiles(
+        files,
+        fileUploadUrl(ENV.DISCUSSION?.ATTACHMENTS_FOLDER_ID)
+      )
+      const newFile = {
+        _id: newFiles[0].id,
+        url: newFiles[0].url,
+        displayName: newFiles[0].display_name,
+      }
+      props.setAttachment(newFile)
+    } catch (err) {
+      setOnFailure(I18n.t('Error uploading file'))
+    } finally {
+      props.setAttachmentToUpload(false)
+    }
+  }
+
   return (
     <Responsive
       match="media"
@@ -43,8 +81,13 @@ export function AttachmentDisplay(props) {
         },
       }}
       render={(_responsiveProps, _matches) =>
-        props.attachment?._id && (
+        props.attachment?._id ? (
           <AttachmentButton attachment={props.attachment} onDeleteItem={removeAttachment} />
+        ) : (
+          <UploadButton
+            attachmentToUpload={props.attachmentToUpload}
+            onAttachmentUpload={addAttachment}
+          />
         )
       }
     />
@@ -61,6 +104,14 @@ AttachmentDisplay.propTypes = {
    * Used to set the attachments prop, if no attachment is set
    */
   setAttachment: PropTypes.func.isRequired,
+  /**
+   * Used to set the setAttachmentsToUpload prop, allows for returning loading state
+   */
+  setAttachmentToUpload: PropTypes.func.isRequired,
+  /**
+   * toggles loading state
+   */
+  attachmentToUpload: PropTypes.bool,
 }
 
 export default AttachmentDisplay
diff --git a/ui/features/discussion_topics_post/react/components/AttachmentDisplay/UploadButton.js b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/UploadButton.js
new file mode 100644
index 00000000000..29ab98fceca
--- /dev/null
+++ b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/UploadButton.js
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2022 - present Instructure, Inc.
+ *
+ * This file is part of Canvas.
+ *
+ * Canvas is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Affero General Public License as published by the Free
+ * Software Foundation, version 3 of the License.
+ *
+ * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU Affero General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import PropTypes from 'prop-types'
+import React from 'react'
+
+import {CondensedButton} from '@instructure/ui-buttons'
+import {IconPaperclipLine} from '@instructure/ui-icons'
+import {Spinner} from '@instructure/ui-spinner'
+import {Text} from '@instructure/ui-text'
+import {useScope as useI18nScope} from '@canvas/i18n'
+
+const I18n = useI18nScope('discussion_topics_post')
+
+export const UploadButton = ({...props}) => {
+  let attachmentInput = null
+  const handleAttachmentClick = () => attachmentInput?.click()
+  return props.attachmentToUpload ? (
+    <>
+      <Spinner
+        renderTitle={I18n.t('Uploading file in progress')}
+        margin="0 0 0 small"
+        size="x-small"
+      />
+    </>
+  ) : (
+    <>
+      <CondensedButton
+        color="primary"
+        renderIcon={<IconPaperclipLine size="small" />}
+        onClick={handleAttachmentClick}
+        data-testid="attach-btn"
+      >
+        <Text weight="bold">{I18n.t('Attach')}</Text>
+      </CondensedButton>
+      <input
+        data-testid="attachment-input"
+        ref={input => (attachmentInput = input)}
+        type="file"
+        style={{display: 'none'}}
+        aria-hidden={true}
+        onChange={props.onAttachmentUpload}
+      />
+    </>
+  )
+}
+
+UploadButton.propTypes = {
+  /**
+   * function that performs on the file after button click, then upload file, upload
+   */
+  onAttachmentUpload: PropTypes.func.isRequired,
+  /**
+   * toggles loading state
+   */
+  attachmentToUpload: PropTypes.bool,
+}
diff --git a/ui/features/discussion_topics_post/react/components/AttachmentDisplay/__tests__/AttachmentDisplay.test.js b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/__tests__/AttachmentDisplay.test.js
index f496ed0a9c0..a0157041e73 100644
--- a/ui/features/discussion_topics_post/react/components/AttachmentDisplay/__tests__/AttachmentDisplay.test.js
+++ b/ui/features/discussion_topics_post/react/components/AttachmentDisplay/__tests__/AttachmentDisplay.test.js
@@ -21,10 +21,23 @@ import {render} from '@testing-library/react'
 import {AttachmentDisplay} from '../AttachmentDisplay'
 
 const setup = props => {
-  return render(<AttachmentDisplay setAttachment={() => {}} {...props} />)
+  return render(
+    <AttachmentDisplay setAttachment={() => {}} setAttachmentToUpload={() => {}} {...props} />
+  )
 }
 
 describe('AttachmentDisplay', () => {
+  it('displays AttachButton when there is no attachment', () => {
+    const {queryByText} = setup()
+    expect(queryByText('Attach')).toBeTruthy()
+  })
+
+  it('only allows one attachment at a time', () => {
+    const {queryByTestId} = setup()
+    expect(queryByTestId('attachment-input')).toHaveAttribute('type', 'file')
+    expect(queryByTestId('attachment-input')).not.toHaveAttribute('multiple')
+  })
+
   it('displays AttachmentButton when there is an attachment', () => {
     const {queryByText} = setup({
       attachment: {
@@ -34,6 +47,7 @@ describe('AttachmentDisplay', () => {
       },
     })
 
+    expect(queryByText('Attach')).toBeFalsy()
     expect(queryByText('file_name.file')).toBeTruthy()
   })
 
@@ -46,6 +60,7 @@ describe('AttachmentDisplay', () => {
       },
     })
 
+    expect(queryByText('Attach')).toBeFalsy()
     expect(queryByText('Fundamentals of Differential E...')).toBeTruthy()
   })
 })
diff --git a/ui/features/discussion_topics_post/react/components/DiscussionEdit/DiscussionEdit.js b/ui/features/discussion_topics_post/react/components/DiscussionEdit/DiscussionEdit.js
index b177b3f7f15..313c8130166 100644
--- a/ui/features/discussion_topics_post/react/components/DiscussionEdit/DiscussionEdit.js
+++ b/ui/features/discussion_topics_post/react/components/DiscussionEdit/DiscussionEdit.js
@@ -52,6 +52,7 @@ export const DiscussionEdit = props => {
   )
 
   const [attachment, setAttachment] = useState(null)
+  const [attachmentToUpload, setAttachmentToUpload] = useState(false)
 
   const rceMentionsIsEnabled = () => {
     return !!ENV.rce_mentions_in_discussions
@@ -226,6 +227,7 @@ export const DiscussionEdit = props => {
                     color="primary"
                     data-testid="DiscussionEdit-submit"
                     key="rce-reply-button"
+                    interaction={attachmentToUpload ? 'disabled' : 'enabled'}
                   >
                     <Text size="medium">{props.isEdit ? I18n.t('Save') : I18n.t('Reply')}</Text>
                   </Button>
@@ -235,7 +237,12 @@ export const DiscussionEdit = props => {
             return matches.includes('mobile') ? (
               <View as="div" padding={undefined} key="mobileButtons">
                 <View as={responsiveProps.viewAs} padding={responsiveProps.paddingAttachment}>
-                  <AttachmentDisplay attachment={attachment} setAttachment={setAttachment} />
+                  <AttachmentDisplay
+                    attachment={attachment}
+                    setAttachment={setAttachment}
+                    setAttachmentToUpload={setAttachmentToUpload}
+                    attachmentToUpload={attachmentToUpload}
+                  />
                 </View>
                 {rceButtons.reverse()}
               </View>
@@ -243,7 +250,12 @@ export const DiscussionEdit = props => {
               <Flex key="nonMobileButtons">
                 <Flex.Item shouldGrow={true} textAlign="start">
                   <View as={responsiveProps.viewAs} padding={responsiveProps.paddingAttachment}>
-                    <AttachmentDisplay attachment={attachment} setAttachment={setAttachment} />
+                    <AttachmentDisplay
+                      attachment={attachment}
+                      setAttachment={setAttachment}
+                      setAttachmentToUpload={setAttachmentToUpload}
+                      attachmentToUpload={attachmentToUpload}
+                    />
                   </View>
                 </Flex.Item>
                 {ENV.draft_discussions && (
diff --git a/ui/features/discussion_topics_post/react/containers/DiscussionThreadContainer/DiscussionThreadContainer.js b/ui/features/discussion_topics_post/react/containers/DiscussionThreadContainer/DiscussionThreadContainer.js
index 006d03de4a3..ae3a854f2c1 100644
--- a/ui/features/discussion_topics_post/react/containers/DiscussionThreadContainer/DiscussionThreadContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/DiscussionThreadContainer/DiscussionThreadContainer.js
@@ -288,6 +288,7 @@ export const DiscussionThreadContainer = props => {
       variables: {
         discussionEntryId: props.discussionEntry._id,
         message,
+        fileId,
         removeAttachment: !fileId,
       },
     })
@@ -325,7 +326,7 @@ export const DiscussionThreadContainer = props => {
     }
   }, [threadRefCurrent, props.discussionEntry.entryParticipant.read, props])
 
-  const onReplySubmit = (message, isAnonymousAuthor, includeReplyPreview) => {
+  const onReplySubmit = (message, fileId, isAnonymousAuthor, includeReplyPreview) => {
     createDiscussionEntry({
       variables: {
         discussionTopicId: ENV.discussion_topic_id,
@@ -334,6 +335,7 @@ export const DiscussionThreadContainer = props => {
           props.discussionEntry.rootEntryId !== props.discussionEntry.parentId
             ? props.discussionEntry.parentId
             : props.discussionEntry._id,
+        fileId,
         isAnonymousAuthor,
         includeReplyPreview,
         message,
@@ -490,8 +492,8 @@ export const DiscussionThreadContainer = props => {
                 <DiscussionEdit
                   discussionAnonymousState={props.discussionTopic?.anonymousState}
                   canReplyAnonymously={props.discussionTopic?.canReplyAnonymously}
-                  onSubmit={(message, includeReplyPreview, _fileId, anonymousAuthorState) => {
-                    onReplySubmit(message, anonymousAuthorState, includeReplyPreview)
+                  onSubmit={(message, includeReplyPreview, fileId, anonymousAuthorState) => {
+                    onReplySubmit(message, fileId, anonymousAuthorState, includeReplyPreview)
                   }}
                   onCancel={() => setEditorExpanded(false)}
                   quotedEntry={buildQuotedReply([props.discussionEntry], replyFromId)}
diff --git a/ui/features/discussion_topics_post/react/containers/DiscussionTopicContainer/DiscussionTopicContainer.js b/ui/features/discussion_topics_post/react/containers/DiscussionTopicContainer/DiscussionTopicContainer.js
index 2118be67ca0..a5c3d1cab40 100644
--- a/ui/features/discussion_topics_post/react/containers/DiscussionTopicContainer/DiscussionTopicContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/DiscussionTopicContainer/DiscussionTopicContainer.js
@@ -496,11 +496,11 @@ export const DiscussionTopicContainer = ({createDiscussionEntry, ...props}) => {
                               onSubmit={(
                                 message,
                                 _includeReplyPreview,
-                                _fileId,
+                                fileId,
                                 anonymousAuthorState
                               ) => {
                                 if (createDiscussionEntry) {
-                                  createDiscussionEntry(message, anonymousAuthorState)
+                                  createDiscussionEntry(message, fileId, anonymousAuthorState)
                                   setExpandedReply(false)
                                   props.onDiscussionReplyPost()
                                 }
diff --git a/ui/features/discussion_topics_post/react/containers/IsolatedThreadsContainer/IsolatedThreadsContainer.js b/ui/features/discussion_topics_post/react/containers/IsolatedThreadsContainer/IsolatedThreadsContainer.js
index e9a61171ccb..f0b427a09f4 100644
--- a/ui/features/discussion_topics_post/react/containers/IsolatedThreadsContainer/IsolatedThreadsContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/IsolatedThreadsContainer/IsolatedThreadsContainer.js
@@ -263,6 +263,7 @@ const IsolatedThreadContainer = props => {
       variables: {
         discussionEntryId: props.discussionEntry._id,
         message,
+        fileId,
         removeAttachment: !fileId,
       },
     })
diff --git a/ui/features/discussion_topics_post/react/containers/IsolatedViewContainer/IsolatedViewContainer.js b/ui/features/discussion_topics_post/react/containers/IsolatedViewContainer/IsolatedViewContainer.js
index 71837f54793..b2afe00c590 100644
--- a/ui/features/discussion_topics_post/react/containers/IsolatedViewContainer/IsolatedViewContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/IsolatedViewContainer/IsolatedViewContainer.js
@@ -197,13 +197,14 @@ export const IsolatedViewContainer = props => {
     window.open(getSpeedGraderUrl(discussionEntry.author._id), '_blank')
   }
 
-  const onReplySubmit = (message, includeReplyPreview, replyId, isAnonymousAuthor) => {
+  const onReplySubmit = (message, fileId, includeReplyPreview, replyId, isAnonymousAuthor) => {
     createDiscussionEntry({
       variables: {
         discussionTopicId: props.discussionTopic._id,
         replyFromEntryId: replyId,
         isAnonymousAuthor,
         message,
+        fileId,
         includeReplyPreview,
         courseID: ENV.course_id,
       },
@@ -420,9 +421,10 @@ export const IsolatedViewContainer = props => {
               <DiscussionEdit
                 discussionAnonymousState={props.discussionTopic?.anonymousState}
                 canReplyAnonymously={props.discussionTopic?.canReplyAnonymously}
-                onSubmit={(message, includeReplyPreview, _fileId, anonymousAuthorState) => {
+                onSubmit={(message, includeReplyPreview, fileId, anonymousAuthorState) => {
                   onReplySubmit(
                     message,
+                    fileId,
                     includeReplyPreview,
                     props.replyFromId,
                     anonymousAuthorState
diff --git a/ui/features/discussion_topics_post/react/containers/SplitScreenThreadsContainer/SplitScreenThreadsContainer.js b/ui/features/discussion_topics_post/react/containers/SplitScreenThreadsContainer/SplitScreenThreadsContainer.js
index 278a647899e..344ea0e6a42 100644
--- a/ui/features/discussion_topics_post/react/containers/SplitScreenThreadsContainer/SplitScreenThreadsContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/SplitScreenThreadsContainer/SplitScreenThreadsContainer.js
@@ -263,6 +263,7 @@ const SplitScreenThreadContainer = props => {
       variables: {
         discussionEntryId: props.discussionEntry._id,
         message,
+        fileId,
         removeAttachment: !fileId,
       },
     })
diff --git a/ui/features/discussion_topics_post/react/containers/SplitScreenViewContainer/SplitScreenViewContainer.js b/ui/features/discussion_topics_post/react/containers/SplitScreenViewContainer/SplitScreenViewContainer.js
index b59f4112cd8..65286c72ea6 100644
--- a/ui/features/discussion_topics_post/react/containers/SplitScreenViewContainer/SplitScreenViewContainer.js
+++ b/ui/features/discussion_topics_post/react/containers/SplitScreenViewContainer/SplitScreenViewContainer.js
@@ -198,13 +198,14 @@ export const SplitScreenViewContainer = props => {
     window.open(getSpeedGraderUrl(discussionEntry.author._id), '_blank')
   }
 
-  const onReplySubmit = (message, includeReplyPreview, replyId, isAnonymousAuthor) => {
+  const onReplySubmit = (message, fileId, includeReplyPreview, replyId, isAnonymousAuthor) => {
     createDiscussionEntry({
       variables: {
         discussionTopicId: props.discussionTopic._id,
         replyFromEntryId: replyId,
         isAnonymousAuthor,
         message,
+        fileId,
         includeReplyPreview,
         courseID: ENV.course_id,
       },
@@ -421,9 +422,10 @@ export const SplitScreenViewContainer = props => {
               <DiscussionEdit
                 discussionAnonymousState={props.discussionTopic?.anonymousState}
                 canReplyAnonymously={props.discussionTopic?.canReplyAnonymously}
-                onSubmit={(message, includeReplyPreview, _fileId, anonymousAuthorState) => {
+                onSubmit={(message, includeReplyPreview, fileId, anonymousAuthorState) => {
                   onReplySubmit(
                     message,
+                    fileId,
                     includeReplyPreview,
                     props.replyFromId,
                     anonymousAuthorState