diff --git a/lib/src/room.dart b/lib/src/room.dart
index dd7c6825..e6e92327 100644
--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@@ -710,6 +710,7 @@ class Room {
     String? threadRootEventId,
     String? threadLastEventId,
     StringBuffer? commandStdout,
+    bool addMentions = true,
   }) {
     if (parseCommands) {
       return client.parseAndRunCommand(
@@ -727,6 +728,41 @@ class Room {
       'msgtype': msgtype,
       'body': message,
     };
+
+    if (addMentions) {
+      var potentialMentions = message
+          .split('@')
+          .map(
+            (text) => text.startsWith('[')
+                ? '@${text.split(']').first}]'
+                : '@${text.split(RegExp(r'\s+')).first}',
+          )
+          .toList()
+        ..removeAt(0);
+
+      final hasRoomMention = potentialMentions.remove('@room');
+
+      potentialMentions = potentialMentions
+          .map(
+            (mention) =>
+                mention.isValidMatrixId ? mention : getMention(mention),
+          )
+          .nonNulls
+          .toSet() // Deduplicate
+          .toList()
+        ..remove(client.userID); // We should never mention ourself.
+
+      // https://spec.matrix.org/v1.7/client-server-api/#mentioning-the-replied-to-user
+      if (inReplyTo != null) potentialMentions.add(inReplyTo.senderId);
+
+      if (hasRoomMention || potentialMentions.isNotEmpty) {
+        event['m.mentions'] = {
+          if (hasRoomMention) 'room': true,
+          if (potentialMentions.isNotEmpty) 'user_ids': potentialMentions,
+        };
+      }
+    }
+
     if (parseMarkdown) {
       final html = markdown(
         event['body'],
diff --git a/test/commands_test.dart b/test/commands_test.dart
index 238c00cb..6efc34e6 100644
--- a/test/commands_test.dart
+++ b/test/commands_test.dart
@@ -243,6 +243,9 @@ void main() {
       expect(sent, {
         'msgtype': 'm.text',
         'body': '> <@test:fakeServer.notExisting> reply\n\nreply',
+        'm.mentions': {
+          'user_ids': ['@test:fakeServer.notExisting'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!1234:fakeServer.notExisting/\$parent_event">In reply to</a> <a href="https://matrix.to/#/@test:fakeServer.notExisting">@test:fakeServer.notExisting</a><br>reply</blockquote></mx-reply>reply',
diff --git a/test/event_test.dart b/test/event_test.dart
index a5166ce9..e3edae90 100644
--- a/test/event_test.dart
+++ b/test/event_test.dart
@@ -2960,7 +2960,7 @@ void main() async {
             'm.mentions': {
               'user_ids': ['@alice:matrix.org'],
               'room': false,
-            }
+            },
           },
           'event_id': '\$143273582443PhrSn:example.org',
           'origin_server_ts': 1432735824653,
diff --git a/test/room_test.dart b/test/room_test.dart
index 01fe4d20..175b3459 100644
--- a/test/room_test.dart
+++ b/test/room_test.dart
@@ -1038,6 +1038,36 @@ void main() {
       });
     });
 
+    test('sendEvent with room mention', () async {
+      FakeMatrixApi.calledEndpoints.clear();
+      final resp = await room.sendTextEvent(
+        'Hello world @room',
+        txid: 'testtxid',
+        addMentions: true,
+      );
+      expect(resp?.startsWith('\$event'), true);
+      final entry = FakeMatrixApi.calledEndpoints.entries
+          .firstWhere((p) => p.key.contains('/send/m.room.message/'));
+      final content = json.decode(entry.value.first);
+      expect(content['m.mentions'], {'room': true});
+    });
+
+    test('sendEvent with user mention', () async {
+      FakeMatrixApi.calledEndpoints.clear();
+      final resp = await room.sendTextEvent(
+        'Hello world @[Alice Margatroid]',
+        addMentions: true,
+        txid: 'testtxid',
+      );
+      expect(resp?.startsWith('\$event'), true);
+      final entry = FakeMatrixApi.calledEndpoints.entries
+          .firstWhere((p) => p.key.contains('/send/m.room.message/'));
+      final content = json.decode(entry.value.first);
+      expect(content['m.mentions'], {
+        'user_ids': ['@alice:matrix.org'],
+      });
+    });
+
     test('send edit', () async {
       FakeMatrixApi.calledEndpoints.clear();
       final dynamic resp = await room.sendTextEvent(
@@ -1089,6 +1119,9 @@ void main() {
       expect(content, {
         'body': '> <@alice:example.org> Blah\n\nHello world',
         'msgtype': 'm.text',
+        'm.mentions': {
+          'user_ids': ['@alice:example.org'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>Blah</blockquote></mx-reply>Hello world',
@@ -1125,6 +1158,9 @@ void main() {
         'body':
             '> <@alice:example.org> <b>Blah</b>\n> beep\n\nHello world\nfox',
         'msgtype': 'm.text',
+        'm.mentions': {
+          'user_ids': ['@alice:example.org'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>&lt;b&gt;Blah&lt;&#47;b&gt;<br>beep</blockquote></mx-reply>Hello world<br/>fox',
@@ -1162,6 +1198,9 @@ void main() {
       expect(content, {
         'body': '> <@alice:example.org> plaintext meow\n\nHello world',
         'msgtype': 'm.text',
+        'm.mentions': {
+          'user_ids': ['@alice:example.org'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>meow</blockquote></mx-reply>Hello world',
@@ -1197,6 +1236,9 @@ void main() {
       expect(content, {
         'body': '> <@alice:example.org> Hey @\u{200b}room\n\nHello world',
         'msgtype': 'm.text',
+        'm.mentions': {
+          'user_ids': ['@alice:example.org'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>Hey @room</blockquote></mx-reply>Hello world',
@@ -1214,6 +1256,9 @@ void main() {
           'content': {
             'body': '> <@alice:example.org> Hey\n\nHello world',
             'msgtype': 'm.text',
+            'm.mentions': {
+              'user_ids': ['@alice:example.org'],
+            },
             'format': 'org.matrix.custom.html',
             'formatted_body':
                 '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>Hey</blockquote></mx-reply>Hello world',
@@ -1238,6 +1283,9 @@ void main() {
       expect(content, {
         'body': '> <@alice:example.org> Hello world\n\nFox',
         'msgtype': 'm.text',
+        'm.mentions': {
+          'user_ids': ['@alice:example.org'],
+        },
         'format': 'org.matrix.custom.html',
         'formatted_body':
             '<mx-reply><blockquote><a href="https://matrix.to/#/!localpart:server.abc/\$replyEvent">In reply to</a> <a href="https://matrix.to/#/@alice:example.org">@alice:example.org</a><br>Hello world</blockquote></mx-reply>Fox',
@@ -1296,7 +1344,7 @@ void main() {
     test('sendFileEvent', () async {
       final testFile = MatrixFile(bytes: Uint8List(0), name: 'file.jpeg');
       final resp = await room.sendFileEvent(testFile, txid: 'testtxid');
-      expect(resp.toString(), '\$event10');
+      expect(resp.toString(), '\$event12');
     });
 
     test('pushRuleState', () async {