diff --git a/lib/shared/markdown.js b/lib/shared/markdown.js
--- a/lib/shared/markdown.js
+++ b/lib/shared/markdown.js
@@ -2,8 +2,15 @@
 
 import invariant from 'invariant';
 
-import { markdownMentionRegex } from './mention-utils.js';
-import type { RelativeMemberInfo } from '../types/thread-types.js';
+import {
+  markdownMentionRegex,
+  decodeChatMentionText,
+} from './mention-utils.js';
+import type {
+  RelativeMemberInfo,
+  ResolvedThreadInfo,
+  ChatMentionCandidates,
+} from '../types/thread-types.js';
 
 // simple-markdown types
 export type State = {
@@ -218,6 +225,24 @@
   return match;
 }
 
+function parseChatMention(
+  chatMentionCandidates: ChatMentionCandidates,
+  capture: Capture,
+): {
+  threadInfo: ?ResolvedThreadInfo,
+  content: string,
+  hasAccessToChat: boolean,
+} {
+  const threadInfo = chatMentionCandidates[capture[2]];
+  const threadName = threadInfo?.uiName ?? decodeChatMentionText(capture[3]);
+  const content = `@${threadName}`;
+  return {
+    threadInfo,
+    content,
+    hasAccessToChat: !!threadInfo,
+  };
+}
+
 const blockQuoteRegex: RegExp = /^( *>[^\n]+(?:\n[^\n]+)*)(?:\n|$)/;
 const blockQuoteStripFollowingNewlineRegex: RegExp =
   /^( *>[^\n]+(?:\n[^\n]+)*)(?:\n|$){2}/;
@@ -317,4 +342,5 @@
   matchMentions,
   stripSpoilersFromNotifications,
   stripSpoilersFromMarkdownAST,
+  parseChatMention,
 };
diff --git a/lib/shared/mention-utils.js b/lib/shared/mention-utils.js
--- a/lib/shared/mention-utils.js
+++ b/lib/shared/mention-utils.js
@@ -2,13 +2,14 @@
 
 import { oldValidUsernameRegexString } from './account-utils.js';
 import SearchIndex from './search-index.js';
-import { threadOtherMembers } from './thread-utils.js';
+import { threadOtherMembers, chatNameMaxLength } from './thread-utils.js';
 import { stringForUserExplicit } from './user-utils.js';
 import { threadTypes } from '../types/thread-types-enum.js';
 import {
   type ThreadInfo,
   type RelativeMemberInfo,
 } from '../types/thread-types.js';
+import { idSchemaRegex } from '../utils/validation-utils.js';
 
 export type TypeaheadMatchedStrings = {
   +textBeforeAtSymbol: string,
@@ -35,6 +36,13 @@
   'g',
 );
 
+const chatMentionRegexString = `^(?<!\\\\)(@\\[\\[(${idSchemaRegex}):(.{1,${chatNameMaxLength}}?)(?<!\\\\)\\]\\])`;
+const chatMentionRegex: RegExp = new RegExp(chatMentionRegexString);
+
+function decodeChatMentionText(text: string): string {
+  return text.replace(/\\]/g, ']');
+}
+
 function extractMentionsFromText(text: string): string[] {
   const iterator = text.matchAll(mentionsExtractionRegex);
   return [...iterator].map(matches => matches[2]);
@@ -117,4 +125,6 @@
   getNewTextAndSelection,
   getTypeaheadRegexMatches,
   getMentionsCandidates,
+  chatMentionRegex,
+  decodeChatMentionText,
 };