diff --git a/src/autocomplete/PeopleAutocomplete.js b/src/autocomplete/PeopleAutocomplete.js
index 0e387d54992..3f92013c62c 100644
--- a/src/autocomplete/PeopleAutocomplete.js
+++ b/src/autocomplete/PeopleAutocomplete.js
@@ -3,9 +3,9 @@
 import React, { PureComponent } from 'react';
 import { SectionList } from 'react-native';
 
-import type { User, UserId, UserGroup, Dispatch } from '../types';
+import type { MutedUsersState, User, UserId, UserGroup, Dispatch } from '../types';
 import { connect } from '../react-redux';
-import { getSortedUsers, getUserGroups } from '../selectors';
+import { getMutedUsers, getSortedUsers, getUserGroups } from '../selectors';
 import {
   type AutocompleteOption,
   getAutocompleteSuggestion,
@@ -20,6 +20,7 @@ type Props = $ReadOnly<{|
   dispatch: Dispatch,
   filter: string,
   onAutocomplete: (name: string) => void,
+  mutedUsers: MutedUsersState,
   ownUserId: UserId,
   users: User[],
   userGroups: UserGroup[],
@@ -44,9 +45,9 @@ class PeopleAutocomplete extends PureComponent<Props> {
   };
 
   render() {
-    const { filter, ownUserId, users, userGroups } = this.props;
+    const { filter, mutedUsers, ownUserId, users, userGroups } = this.props;
     const filteredUserGroups = getAutocompleteUserGroupSuggestions(userGroups, filter);
-    const filteredUsers = getAutocompleteSuggestion(users, filter, ownUserId);
+    const filteredUsers = getAutocompleteSuggestion(users, filter, ownUserId, mutedUsers);
 
     if (filteredUserGroups.length + filteredUsers.length === 0) {
       return null;
@@ -105,6 +106,7 @@ class PeopleAutocomplete extends PureComponent<Props> {
 }
 
 export default connect(state => ({
+  mutedUsers: getMutedUsers(state),
   ownUserId: getOwnUserId(state),
   users: getSortedUsers(state),
   userGroups: getUserGroups(state),
diff --git a/src/users/__tests__/userHelpers-test.js b/src/users/__tests__/userHelpers-test.js
index c41bd163d43..27440a0fb24 100644
--- a/src/users/__tests__/userHelpers-test.js
+++ b/src/users/__tests__/userHelpers-test.js
@@ -1,5 +1,6 @@
 /* @flow strict-local */
 import deepFreeze from 'deep-freeze';
+import Immutable from 'immutable';
 
 import {
   sortUserList,
@@ -61,7 +62,12 @@ describe('getAutocompleteSuggestion', () => {
   test('empty input results in empty list', () => {
     const users = deepFreeze([]);
 
-    const filteredUsers = getAutocompleteSuggestion(users, 'some filter', eg.selfUser.user_id);
+    const filteredUsers = getAutocompleteSuggestion(
+      users,
+      'some filter',
+      eg.selfUser.user_id,
+      Immutable.Map(),
+    );
     expect(filteredUsers).toBe(users);
   });
 
@@ -74,7 +80,20 @@ describe('getAutocompleteSuggestion', () => {
       { user_id: -1, full_name: 'all', email: '(Notify everyone)' },
       someGuyUser,
     ];
-    const filteredUsers = getAutocompleteSuggestion(users, '', meUser.user_id);
+    const filteredUsers = getAutocompleteSuggestion(users, '', meUser.user_id, Immutable.Map());
+    expect(filteredUsers).toEqual(shouldMatch);
+  });
+
+  test('filters out muted user', () => {
+    const mutedUser = eg.makeUser({ name: 'Muted User' });
+    const meUser = eg.makeUser({ name: 'Me' });
+    const users = deepFreeze([mutedUser, meUser]);
+
+    const mutedUsers = Immutable.Map([[mutedUser.user_id, 0]]);
+
+    const shouldMatch = [{ user_id: -1, full_name: 'all', email: '(Notify everyone)' }];
+
+    const filteredUsers = getAutocompleteSuggestion(users, '', meUser.user_id, mutedUsers);
     expect(filteredUsers).toEqual(shouldMatch);
   });
 
@@ -87,7 +106,12 @@ describe('getAutocompleteSuggestion', () => {
     const allUsers = deepFreeze([user1, user2, user3, user4, user5]);
 
     const shouldMatch = [user1, user2, user3, user5];
-    const filteredUsers = getAutocompleteSuggestion(allUsers, 'match', eg.selfUser.user_id);
+    const filteredUsers = getAutocompleteSuggestion(
+      allUsers,
+      'match',
+      eg.selfUser.user_id,
+      Immutable.Map(),
+    );
     expect(filteredUsers).toEqual(shouldMatch);
   });
 
@@ -127,7 +151,12 @@ describe('getAutocompleteSuggestion', () => {
       user11, // have priority because of 'ma' contains in name
       user4, // email contains 'ma'
     ];
-    const filteredUsers = getAutocompleteSuggestion(allUsers, 'ma', eg.selfUser.user_id);
+    const filteredUsers = getAutocompleteSuggestion(
+      allUsers,
+      'ma',
+      eg.selfUser.user_id,
+      Immutable.Map(),
+    );
     expect(filteredUsers).toEqual(shouldMatch);
   });
 });
diff --git a/src/users/userHelpers.js b/src/users/userHelpers.js
index c1b2d531b8e..98a516c33c9 100644
--- a/src/users/userHelpers.js
+++ b/src/users/userHelpers.js
@@ -1,7 +1,15 @@
 /* @flow strict-local */
 import uniqby from 'lodash.uniqby';
 
-import type { UserPresence, User, UserId, UserGroup, PresenceState, UserOrBot } from '../types';
+import type {
+  MutedUsersState,
+  UserPresence,
+  User,
+  UserId,
+  UserGroup,
+  PresenceState,
+  UserOrBot,
+} from '../types';
 import { ensureUnreachable } from '../types';
 import { statusFromPresence } from '../utils/presence';
 import { makeUserId } from '../api/idTypes';
@@ -121,6 +129,7 @@ export const getAutocompleteSuggestion = (
   users: $ReadOnlyArray<AutocompleteOption>,
   filter: string = '',
   ownUserId: UserId,
+  mutedUsers: MutedUsersState,
 ): $ReadOnlyArray<AutocompleteOption> => {
   if (users.length === 0) {
     return users;
@@ -130,7 +139,8 @@ export const getAutocompleteSuggestion = (
   const initials = filterUserByInitials(allAutocompleteOptions, filter, ownUserId);
   const contains = filterUserThatContains(allAutocompleteOptions, filter, ownUserId);
   const matchesEmail = filterUserMatchesEmail(users, filter, ownUserId);
-  return getUniqueUsers([...startWith, ...initials, ...contains, ...matchesEmail]);
+  const candidates = getUniqueUsers([...startWith, ...initials, ...contains, ...matchesEmail]);
+  return candidates.filter(user => !mutedUsers.has(user.user_id));
 };
 
 export const getAutocompleteUserGroupSuggestions = (