diff --git a/extensions/mentions/extend.php b/extensions/mentions/extend.php
index 178330e33..794503693 100644
--- a/extensions/mentions/extend.php
+++ b/extensions/mentions/extend.php
@@ -12,10 +12,11 @@ namespace Flarum\Mentions;
 use Flarum\Api\Controller;
 use Flarum\Api\Serializer\BasicPostSerializer;
 use Flarum\Api\Serializer\BasicUserSerializer;
+use Flarum\Api\Serializer\CurrentUserSerializer;
+use Flarum\Api\Serializer\GroupSerializer;
 use Flarum\Api\Serializer\PostSerializer;
 use Flarum\Extend;
-use Flarum\Mentions\Notification\PostMentionedBlueprint;
-use Flarum\Mentions\Notification\UserMentionedBlueprint;
+use Flarum\Group\Group;
 use Flarum\Post\Event\Deleted;
 use Flarum\Post\Event\Hidden;
 use Flarum\Post\Event\Posted;
@@ -37,13 +38,16 @@ return [
         ->configure(ConfigureMentions::class)
         ->render(Formatter\FormatPostMentions::class)
         ->render(Formatter\FormatUserMentions::class)
+        ->render(Formatter\FormatGroupMentions::class)
         ->unparse(Formatter\UnparsePostMentions::class)
-        ->unparse(Formatter\UnparseUserMentions::class),
+        ->unparse(Formatter\UnparseUserMentions::class)
+        ->parse(Formatter\CheckPermissions::class),
 
     (new Extend\Model(Post::class))
         ->belongsToMany('mentionedBy', Post::class, 'post_mentions_post', 'mentions_post_id', 'post_id')
         ->belongsToMany('mentionsPosts', Post::class, 'post_mentions_post', 'post_id', 'mentions_post_id')
-        ->belongsToMany('mentionsUsers', User::class, 'post_mentions_user', 'post_id', 'mentions_user_id'),
+        ->belongsToMany('mentionsUsers', User::class, 'post_mentions_user', 'post_id', 'mentions_user_id')
+        ->belongsToMany('mentionsGroups', Group::class, 'post_mentions_group', 'post_id', 'mentions_group_id'),
 
     new Extend\Locales(__DIR__.'/locale'),
 
@@ -51,25 +55,28 @@ return [
         ->namespace('flarum-mentions', __DIR__.'/views'),
 
     (new Extend\Notification())
-        ->type(PostMentionedBlueprint::class, PostSerializer::class, ['alert'])
-        ->type(UserMentionedBlueprint::class, PostSerializer::class, ['alert']),
+        ->type(Notification\PostMentionedBlueprint::class, PostSerializer::class, ['alert'])
+        ->type(Notification\UserMentionedBlueprint::class, PostSerializer::class, ['alert'])
+        ->type(Notification\GroupMentionedBlueprint::class, PostSerializer::class, ['alert']),
 
     (new Extend\ApiSerializer(BasicPostSerializer::class))
         ->hasMany('mentionedBy', BasicPostSerializer::class)
         ->hasMany('mentionsPosts', BasicPostSerializer::class)
-        ->hasMany('mentionsUsers', BasicUserSerializer::class),
+        ->hasMany('mentionsUsers', BasicUserSerializer::class)
+        ->hasMany('mentionsGroups', GroupSerializer::class),
 
     (new Extend\ApiController(Controller\ShowDiscussionController::class))
         ->addInclude(['posts.mentionedBy', 'posts.mentionedBy.user', 'posts.mentionedBy.discussion'])
         ->load([
             'posts.mentionsUsers', 'posts.mentionsPosts', 'posts.mentionsPosts.user', 'posts.mentionedBy',
             'posts.mentionedBy.mentionsPosts', 'posts.mentionedBy.mentionsPosts.user', 'posts.mentionedBy.mentionsUsers',
+            'posts.mentionsGroups'
         ]),
 
     (new Extend\ApiController(Controller\ListDiscussionsController::class))
         ->load([
-            'firstPost.mentionsUsers', 'firstPost.mentionsPosts', 'firstPost.mentionsPosts.user',
-            'lastPost.mentionsUsers', 'lastPost.mentionsPosts', 'lastPost.mentionsPosts.user'
+            'firstPost.mentionsUsers', 'firstPost.mentionsPosts', 'firstPost.mentionsPosts.user', 'firstPost.mentionsGroups',
+            'lastPost.mentionsUsers', 'lastPost.mentionsPosts', 'lastPost.mentionsPosts.user', 'lastPost.mentionsGroups'
         ]),
 
     (new Extend\ApiController(Controller\ShowPostController::class))
@@ -80,13 +87,16 @@ return [
         ->load([
             'mentionsUsers', 'mentionsPosts', 'mentionsPosts.user', 'mentionedBy',
             'mentionedBy.mentionsPosts', 'mentionedBy.mentionsPosts.user', 'mentionedBy.mentionsUsers',
+            'mentionsGroups'
         ]),
 
     (new Extend\ApiController(Controller\CreatePostController::class))
-        ->addInclude(['mentionsPosts', 'mentionsPosts.mentionedBy']),
+        ->addInclude(['mentionsPosts', 'mentionsPosts.mentionedBy'])
+        ->addOptionalInclude('mentionsGroups'),
 
     (new Extend\ApiController(Controller\UpdatePostController::class))
-        ->addInclude(['mentionsPosts', 'mentionsPosts.mentionedBy']),
+        ->addInclude(['mentionsPosts', 'mentionsPosts.mentionedBy'])
+        ->addOptionalInclude('mentionsGroups'),
 
     (new Extend\ApiController(Controller\AbstractSerializeController::class))
         ->prepareDataForSerialization(FilterVisiblePosts::class),
@@ -103,4 +113,9 @@ return [
 
     (new Extend\Filter(PostFilterer::class))
         ->addFilter(Filter\MentionedFilter::class),
+
+    (new Extend\ApiSerializer(CurrentUserSerializer::class))
+        ->attribute('canMentionGroups', function (CurrentUserSerializer $serializer, User $user, array $attributes): bool {
+            return $user->can('mentionGroups');
+        })
 ];
diff --git a/extensions/mentions/js/src/admin/index.js b/extensions/mentions/js/src/admin/index.js
index e34d92cbc..f8bc9c9fc 100644
--- a/extensions/mentions/js/src/admin/index.js
+++ b/extensions/mentions/js/src/admin/index.js
@@ -1,10 +1,20 @@
 import app from 'flarum/admin/app';
 
 app.initializers.add('flarum-mentions', function () {
-  app.extensionData.for('flarum-mentions').registerSetting({
-    setting: 'flarum-mentions.allow_username_format',
-    type: 'boolean',
-    label: app.translator.trans('flarum-mentions.admin.settings.allow_username_format_label'),
-    help: app.translator.trans('flarum-mentions.admin.settings.allow_username_format_text'),
-  });
+  app.extensionData
+    .for('flarum-mentions')
+    .registerSetting({
+      setting: 'flarum-mentions.allow_username_format',
+      type: 'boolean',
+      label: app.translator.trans('flarum-mentions.admin.settings.allow_username_format_label'),
+      help: app.translator.trans('flarum-mentions.admin.settings.allow_username_format_text'),
+    })
+    .registerPermission(
+      {
+        permission: 'mentionGroups',
+        label: app.translator.trans('flarum-mentions.admin.permissions.mention_groups_label'),
+        icon: 'fas fa-at',
+      },
+      'start'
+    );
 });
diff --git a/extensions/mentions/js/src/forum/addComposerAutocomplete.js b/extensions/mentions/js/src/forum/addComposerAutocomplete.js
index f1eec3122..78588a4da 100644
--- a/extensions/mentions/js/src/forum/addComposerAutocomplete.js
+++ b/extensions/mentions/js/src/forum/addComposerAutocomplete.js
@@ -10,6 +10,8 @@ import highlight from 'flarum/common/helpers/highlight';
 import KeyboardNavigatable from 'flarum/forum/utils/KeyboardNavigatable';
 import { truncate } from 'flarum/common/utils/string';
 import { throttle } from 'flarum/common/utils/throttleDebounce';
+import Badge from 'flarum/common/components/Badge';
+import Group from 'flarum/common/models/Group';
 
 import AutocompleteDropdown from './fragments/AutocompleteDropdown';
 import getMentionText from './utils/getMentionText';
@@ -29,6 +31,7 @@ const throttledSearch = throttle(
 
         buildSuggestions();
       });
+
       searched.push(typedLower);
     }
   }
@@ -66,6 +69,13 @@ export default function addComposerAutocomplete() {
     const returnedUsers = Array.from(app.store.all('users'));
     const returnedUserIds = new Set(returnedUsers.map((u) => u.id()));
 
+    // Store groups, but exclude the two virtual groups - 'Guest' and 'Member'.
+    const returnedGroups = Array.from(
+      app.store.all('groups').filter((group) => {
+        return group.id() != Group.GUEST_ID && group.id() != Group.MEMBER_ID;
+      })
+    );
+
     const applySuggestion = (replacement) => {
       this.attrs.composer.editor.replaceBeforeCursor(absMentionStart - 1, replacement + ' ');
 
@@ -124,12 +134,41 @@ export default function addComposerAutocomplete() {
           );
         };
 
+        const makeGroupSuggestion = function (group, replacement, content, className = '') {
+          let groupName = group.namePlural().toLowerCase();
+
+          if (typed) {
+            groupName = highlight(groupName, typed);
+          }
+
+          return (
+            <button
+              className={'PostPreview ' + className}
+              onclick={() => applySuggestion(replacement)}
+              onmouseenter={function () {
+                dropdown.setIndex($(this).parent().index());
+              }}
+            >
+              <span className="PostPreview-content">
+                <Badge class={`Avatar Badge Badge--group--${group.id()} Badge-icon `} color={group.color()} type="group" icon={group.icon()} />
+                <span className="username">{groupName}</span>
+              </span>
+            </button>
+          );
+        };
+
         const userMatches = function (user) {
           const names = [user.username(), user.displayName()];
 
           return names.some((name) => name.toLowerCase().substr(0, typed.length) === typed);
         };
 
+        const groupMatches = function (group) {
+          const names = [group.nameSingular(), group.namePlural()];
+
+          return names.some((name) => name.toLowerCase().substr(0, typed.length) === typed);
+        };
+
         const buildSuggestions = () => {
           const suggestions = [];
 
@@ -141,6 +180,15 @@ export default function addComposerAutocomplete() {
 
               suggestions.push(makeSuggestion(user, getMentionText(user), '', 'MentionsDropdown-user'));
             });
+
+            // ... or groups.
+            if (app.session?.user?.canMentionGroups()) {
+              returnedGroups.forEach((group) => {
+                if (!groupMatches(group)) return;
+
+                suggestions.push(makeGroupSuggestion(group, getMentionText(undefined, undefined, group), '', 'MentionsDropdown-group'));
+              });
+            }
           }
 
           // If the user is replying to a discussion, or if they are editing a
diff --git a/extensions/mentions/js/src/forum/compat.js b/extensions/mentions/js/src/forum/compat.js
index 7ada97757..ee22c6773 100644
--- a/extensions/mentions/js/src/forum/compat.js
+++ b/extensions/mentions/js/src/forum/compat.js
@@ -1,3 +1,4 @@
+import GroupMentionedNotification from './components/GroupMentionedNotification';
 import MentionsUserPage from './components/MentionsUserPage';
 import PostMentionedNotification from './components/PostMentionedNotification';
 import UserMentionedNotification from './components/UserMentionedNotification';
@@ -13,6 +14,7 @@ export default {
   'mentions/components/MentionsUserPage': MentionsUserPage,
   'mentions/components/PostMentionedNotification': PostMentionedNotification,
   'mentions/components/UserMentionedNotification': UserMentionedNotification,
+  'mentions/components/GroupMentionedNotification': GroupMentionedNotification,
   'mentions/fragments/AutocompleteDropdown': AutocompleteDropdown,
   'mentions/fragments/PostQuoteButton': PostQuoteButton,
   'mentions/utils/getCleanDisplayName': getCleanDisplayName,
diff --git a/extensions/mentions/js/src/forum/components/GroupMentionedNotification.js b/extensions/mentions/js/src/forum/components/GroupMentionedNotification.js
new file mode 100644
index 000000000..838038ab9
--- /dev/null
+++ b/extensions/mentions/js/src/forum/components/GroupMentionedNotification.js
@@ -0,0 +1,25 @@
+import app from 'flarum/forum/app';
+import Notification from 'flarum/forum/components/Notification';
+import { truncate } from 'flarum/common/utils/string';
+
+export default class GroupMentionedNotification extends Notification {
+  icon() {
+    return 'fas fa-at';
+  }
+
+  href() {
+    const post = this.attrs.notification.subject();
+
+    return app.route.discussion(post.discussion(), post.number());
+  }
+
+  content() {
+    const user = this.attrs.notification.fromUser();
+
+    return app.translator.trans('flarum-mentions.forum.notifications.group_mentioned_text', { user });
+  }
+
+  excerpt() {
+    return truncate(this.attrs.notification.subject().contentPlain(), 200);
+  }
+}
diff --git a/extensions/mentions/js/src/forum/index.js b/extensions/mentions/js/src/forum/index.js
index ab5392f46..467e98e19 100644
--- a/extensions/mentions/js/src/forum/index.js
+++ b/extensions/mentions/js/src/forum/index.js
@@ -10,11 +10,16 @@ import addPostQuoteButton from './addPostQuoteButton';
 import addComposerAutocomplete from './addComposerAutocomplete';
 import PostMentionedNotification from './components/PostMentionedNotification';
 import UserMentionedNotification from './components/UserMentionedNotification';
+import GroupMentionedNotification from './components/GroupMentionedNotification';
 import UserPage from 'flarum/forum/components/UserPage';
 import LinkButton from 'flarum/common/components/LinkButton';
 import MentionsUserPage from './components/MentionsUserPage';
+import User from 'flarum/common/models/User';
+import Model from 'flarum/common/Model';
 
 app.initializers.add('flarum-mentions', function () {
+  User.prototype.canMentionGroups = Model.attribute('canMentionGroups');
+
   // For every mention of a post inside a post's content, set up a hover handler
   // that shows a preview of the mentioned post.
   addPostMentionPreviews();
@@ -36,6 +41,7 @@ app.initializers.add('flarum-mentions', function () {
 
   app.notificationComponents.postMentioned = PostMentionedNotification;
   app.notificationComponents.userMentioned = UserMentionedNotification;
+  app.notificationComponents.groupMentioned = GroupMentionedNotification;
 
   // Add notification preferences.
   extend(NotificationGrid.prototype, 'notificationTypes', function (items) {
@@ -50,6 +56,12 @@ app.initializers.add('flarum-mentions', function () {
       icon: 'fas fa-at',
       label: app.translator.trans('flarum-mentions.forum.settings.notify_user_mentioned_label'),
     });
+
+    items.add('groupMentioned', {
+      name: 'groupMentioned',
+      icon: 'fas fa-at',
+      label: app.translator.trans('flarum-mentions.forum.settings.notify_group_mentioned_label'),
+    });
   });
 
   // Add mentions tab in user profile
diff --git a/extensions/mentions/js/src/forum/utils/getMentionText.js b/extensions/mentions/js/src/forum/utils/getMentionText.js
index 99e92af30..6a99ee38e 100644
--- a/extensions/mentions/js/src/forum/utils/getMentionText.js
+++ b/extensions/mentions/js/src/forum/utils/getMentionText.js
@@ -1,7 +1,7 @@
 import getCleanDisplayName, { shouldUseOldFormat } from './getCleanDisplayName';
 
 /**
- * Fetches the mention text for a specified user (and optionally a post ID for replies).
+ * Fetches the mention text for a specified user (and optionally a post ID for replies, or group).
  *
  * Automatically determines which mention syntax to be used based on the option in the
  * admin dashboard. Also performs display name clean-up automatically.
@@ -17,9 +17,13 @@ import getCleanDisplayName, { shouldUseOldFormat } from './getCleanDisplayName';
  * @example <caption>Using old syntax</caption>
  * // '@username'
  * getMentionText(User) // User's username is 'username'
+ *
+ * @example <caption>Group mention</caption>
+ * // '@"Mods"#g4'
+ * getMentionText(undefined, undefined, group) // Group display name is 'Mods', group ID is 4
  */
-export default function getMentionText(user, postId) {
-  if (postId === undefined) {
+export default function getMentionText(user, postId, group) {
+  if (user !== undefined && postId === undefined) {
     if (shouldUseOldFormat()) {
       // Plain @username
       const cleanText = getCleanDisplayName(user, false);
@@ -28,9 +32,14 @@ export default function getMentionText(user, postId) {
     // @"Display name"#UserID
     const cleanText = getCleanDisplayName(user);
     return `@"${cleanText}"#${user.id()}`;
-  } else {
+  } else if (user !== undefined && postId !== undefined) {
     // @"Display name"#pPostID
     const cleanText = getCleanDisplayName(user);
     return `@"${cleanText}"#p${postId}`;
+  } else if (group !== undefined) {
+    // @"Name Plural"#gGroupID
+    return `@"${group.namePlural()}"#g${group.id()}`;
+  } else {
+    throw 'No parameters were passed';
   }
 }
diff --git a/extensions/mentions/js/src/forum/utils/textFormatter.js b/extensions/mentions/js/src/forum/utils/textFormatter.js
index 9c6c26c47..415d99907 100644
--- a/extensions/mentions/js/src/forum/utils/textFormatter.js
+++ b/extensions/mentions/js/src/forum/utils/textFormatter.js
@@ -31,3 +31,19 @@ export function filterPostMentions(tag) {
     return true;
   }
 }
+
+export function filterGroupMentions(tag) {
+  if (app.session?.user?.canMentionGroups()) {
+    const group = app.store.getById('groups', tag.getAttribute('id'));
+
+    if (group) {
+      tag.setAttribute('groupname', extractText(group.namePlural()));
+      tag.setAttribute('icon', group.icon());
+      tag.setAttribute('color', group.color());
+
+      return true;
+    }
+  }
+
+  tag.invalidate();
+}
diff --git a/extensions/mentions/less/forum.less b/extensions/mentions/less/forum.less
index e8e211772..0932c60df 100644
--- a/extensions/mentions/less/forum.less
+++ b/extensions/mentions/less/forum.less
@@ -1,4 +1,4 @@
-.PostMention, .UserMention {
+.PostMention, .UserMention, .GroupMention {
   background: @control-bg;
   color: @control-color;
   border-radius: @border-radius;
@@ -14,7 +14,7 @@
     color: @link-color;
   }
 }
-.UserMention, .PostMention {
+.UserMention, .PostMention, .GroupMention {
   &--deleted {
     opacity: 0.8;
     filter: grayscale(1);
@@ -97,6 +97,21 @@
   position: absolute;
   .Button--color(@tooltip-color, @tooltip-bg);
 }
+.GroupMention {
+  color: @body-bg;
+
+  .icon {
+    margin-left: 5px;
+  }
+
+  &:hover,
+  &:active {
+    color: @body-bg;
+  }
+}
+.MentionsDropdown .Badge {
+  box-shadow: none;
+}
 
 @media @phone {
   .MentionsDropdown {
diff --git a/extensions/mentions/locale/en.yml b/extensions/mentions/locale/en.yml
index 962baf633..0a1ea3fba 100644
--- a/extensions/mentions/locale/en.yml
+++ b/extensions/mentions/locale/en.yml
@@ -7,6 +7,9 @@ flarum-mentions:
   # Translations in this namespace are used by the admin interface.
   admin:
 
+    # These translations are used in the mentions permissions
+    permissions:
+      mention_groups_label: Mention groups
     # These translations are used in the mentions Settings page.
     settings:
       allow_username_format_label: Allow username mention format (@Username)
@@ -19,7 +22,7 @@ flarum-mentions:
 
     # These translations are used by the composer (reply autocompletion function).
     composer:
-      mention_tooltip: Mention a user or post
+      mention_tooltip: Mention a user, group or post
       reply_to_post_text: "Reply to #{number}"
 
     # These translations are used by the Notifications dropdown, a.k.a. "the bell".
@@ -27,6 +30,7 @@ flarum-mentions:
       others_text: => core.ref.some_others
       post_mentioned_text: "{username} replied to your post"  # Can be pluralized to agree with the number of users!
       user_mentioned_text: "{username} mentioned you"
+      group_mentioned_text: "{username} mentioned a group you're a member of"
 
     # These translations are displayed beneath individual posts.
     post:
@@ -41,6 +45,7 @@ flarum-mentions:
     settings:
       notify_post_mentioned_label: Someone replies to one of my posts
       notify_user_mentioned_label: Someone mentions me in a post
+      notify_group_mentioned_label: Someone mentions a group I'm a member of in a post
 
     # These translations are used in the user profile page and profile popup.
     user:
@@ -50,6 +55,9 @@ flarum-mentions:
     post_mention:
       deleted_text: "[unknown]"
 
+    group_mention:
+      deleted_text: "[unknown group]"
+
   # Translations in this namespace are used in emails sent by the forum.
   email:
 
@@ -80,4 +88,16 @@ flarum-mentions:
         ---
 
         {content}
+    # These translations are used in emails sent when a group is mentioned
+    group_mentioned:
+      subject: "{mentioner_display_name} mentioned a group you're a member of in {title}"
+      body: |
+        Hey {recipient_display_name}!
 
+        {mentioner_display_name} mentioned a group you're a member of in {title}.
+
+        {url}
+
+        ---
+
+        {content}
diff --git a/extensions/mentions/migrations/2022_10_21_000000_create_post_mentions_group_table.php b/extensions/mentions/migrations/2022_10_21_000000_create_post_mentions_group_table.php
new file mode 100644
index 000000000..7ef19646b
--- /dev/null
+++ b/extensions/mentions/migrations/2022_10_21_000000_create_post_mentions_group_table.php
@@ -0,0 +1,29 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Schema\Builder;
+
+return [
+    'up' => function (Builder $schema) {
+        $schema->create('post_mentions_group', function (Blueprint $table) {
+            $table->integer('post_id')->unsigned();
+            $table->integer('mentions_group_id')->unsigned();
+            $table->dateTime('created_at')->useCurrent()->nullable();
+            $table->primary(['post_id', 'mentions_group_id']);
+
+            $table->foreign('post_id')->references('id')->on('posts')->onDelete('cascade');
+            $table->foreign('mentions_group_id')->references('id')->on('groups')->onDelete('cascade');
+        });
+    },
+
+    'down' => function (Builder $schema) {
+        $schema->drop('post_mentions_group');
+    }
+];
diff --git a/extensions/mentions/src/ConfigureMentions.php b/extensions/mentions/src/ConfigureMentions.php
index a85727707..d57904f5e 100644
--- a/extensions/mentions/src/ConfigureMentions.php
+++ b/extensions/mentions/src/ConfigureMentions.php
@@ -9,6 +9,7 @@
 
 namespace Flarum\Mentions;
 
+use Flarum\Group\Group;
 use Flarum\Http\UrlGenerator;
 use Flarum\Post\CommentPost;
 use Flarum\Settings\SettingsRepositoryInterface;
@@ -34,6 +35,7 @@ class ConfigureMentions
     {
         $this->configureUserMentions($config);
         $this->configurePostMentions($config);
+        $this->configureGroupMentions($config);
     }
 
     private function configureUserMentions(Configurator $config)
@@ -136,4 +138,49 @@ class ConfigureMentions
             return true;
         }
     }
+
+    private function configureGroupMentions(Configurator $config)
+    {
+        $tagName = 'GROUPMENTION';
+
+        $tag = $config->tags->add($tagName);
+        $tag->attributes->add('groupname');
+        $tag->attributes->add('icon');
+        $tag->attributes->add('color');
+        $tag->attributes->add('id')->filterChain->append('#uint');
+
+        $tag->template = '
+            <xsl:choose>
+                <xsl:when test="@deleted != 1">
+                    <span class="GroupMention" style="background: {@color}">@<xsl:value-of select="@groupname"/><i class="icon {@icon}"></i></span>
+                </xsl:when>
+                <xsl:otherwise>
+                    <span class="GroupMention GroupMention--deleted" style="background: {@color}">@<xsl:value-of select="@groupname"/><i class="icon {@icon}"></i></span>
+                </xsl:otherwise>
+            </xsl:choose>';
+        $tag->filterChain->prepend([static::class, 'addGroupId'])
+            ->setJS('function(tag) { return flarum.extensions["flarum-mentions"].filterGroupMentions(tag); }');
+
+        $config->Preg->match('/\B@["|“](?<groupname>((?!"#[a-z]{0,3}[0-9]+).)+)["|”]#g(?<id>[0-9]+)\b/', $tagName);
+    }
+
+    /**
+     * @param $tag
+     * @return bool
+     */
+    public static function addGroupId($tag)
+    {
+        $group = Group::find($tag->getAttribute('id'));
+
+        if (isset($group) && ! in_array($group->id, [Group::GUEST_ID, Group::MEMBER_ID])) {
+            $tag->setAttribute('id', $group->id);
+            $tag->setAttribute('groupname', $group->name_plural);
+            $tag->setAttribute('icon', $group->icon ?? 'fas fa-at');
+            $tag->setAttribute('color', $group->color);
+
+            return true;
+        }
+
+        $tag->invalidate();
+    }
 }
diff --git a/extensions/mentions/src/FilterVisiblePosts.php b/extensions/mentions/src/FilterVisiblePosts.php
index 256025ec7..47aec39d2 100755
--- a/extensions/mentions/src/FilterVisiblePosts.php
+++ b/extensions/mentions/src/FilterVisiblePosts.php
@@ -54,8 +54,8 @@ class FilterVisiblePosts
             || $controller instanceof Controller\CreatePostController
             || $controller instanceof Controller\UpdatePostController) {
             $relations = [
-                'mentionsUsers', 'mentionsPosts', 'mentionsPosts.user', 'mentionedBy',
-                'mentionedBy.mentionsPosts', 'mentionedBy.mentionsPosts.user', 'mentionedBy.mentionsUsers'
+                'mentionsUsers', 'mentionsPosts', 'mentionsPosts.user', 'mentionedBy', 'mentionsGroups',
+                'mentionedBy.mentionsPosts', 'mentionedBy.mentionsPosts.user', 'mentionedBy.mentionsUsers', 'mentionedBy.mentionsGroups.group'
             ];
 
             $posts = [$data];
diff --git a/extensions/mentions/src/Formatter/CheckPermissions.php b/extensions/mentions/src/Formatter/CheckPermissions.php
new file mode 100644
index 000000000..c6a899b45
--- /dev/null
+++ b/extensions/mentions/src/Formatter/CheckPermissions.php
@@ -0,0 +1,26 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Mentions\Formatter;
+
+use Flarum\User\User;
+use s9e\TextFormatter\Parser;
+
+class CheckPermissions
+{
+    public function __invoke(Parser $parser, $content, string $text, ?User $actor): string
+    {
+        // Check user has `mentionGroups` permission, if not, remove the `GROUPMENTION` tag from the parser.
+        if ($actor && $actor->cannot('mentionGroups')) {
+            $parser->disableTag('GROUPMENTION');
+        }
+
+        return $text;
+    }
+}
diff --git a/extensions/mentions/src/Formatter/FormatGroupMentions.php b/extensions/mentions/src/Formatter/FormatGroupMentions.php
new file mode 100644
index 000000000..713166cc1
--- /dev/null
+++ b/extensions/mentions/src/Formatter/FormatGroupMentions.php
@@ -0,0 +1,59 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Mentions\Formatter;
+
+use Flarum\Group\Group;
+use Flarum\Post\Post;
+use s9e\TextFormatter\Renderer;
+use s9e\TextFormatter\Utils;
+use Symfony\Contracts\Translation\TranslatorInterface;
+
+class FormatGroupMentions
+{
+    /**
+     * @var TranslatorInterface
+     */
+    private $translator;
+
+    public function __construct(TranslatorInterface $translator)
+    {
+        $this->translator = $translator;
+    }
+
+    /**
+     * Configure rendering for group mentions.
+     *
+     * @param \s9e\TextFormatter\Renderer $renderer
+     * @param mixed $context
+     * @param string $xml
+     * @return string
+     */
+    public function __invoke(Renderer $renderer, $context, string $xml): string
+    {
+        return Utils::replaceAttributes($xml, 'GROUPMENTION', function ($attributes) use ($context) {
+            $group = (($context && isset($context->getRelations()['mentionsGroups'])) || $context instanceof Post)
+            ? $context->mentionsGroups->find($attributes['id'])
+            : Group::find($attributes['id']);
+
+            if ($group) {
+                $attributes['groupname'] = $group->name_plural;
+                $attributes['icon'] = $group->icon ?? 'fas fa-at';
+                $attributes['color'] = $group->color;
+                $attributes['deleted'] = false;
+            } else {
+                $attributes['groupname'] = $this->translator->trans('flarum-mentions.forum.group_mention.deleted_text');
+                $attributes['icon'] = '';
+                $attributes['deleted'] = true;
+            }
+
+            return $attributes;
+        });
+    }
+}
diff --git a/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenInvisible.php b/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenInvisible.php
index e130b1477..fafe2a850 100755
--- a/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenInvisible.php
+++ b/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenInvisible.php
@@ -40,5 +40,8 @@ class UpdateMentionsMetadataWhenInvisible
 
         // Remove post mentions
         $event->post->mentionsPosts()->sync([]);
+
+        // Remove group mentions
+        $event->post->mentionsGroups()->sync([]);
     }
 }
diff --git a/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenVisible.php b/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenVisible.php
index 47a94a610..231f6cfd7 100755
--- a/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenVisible.php
+++ b/extensions/mentions/src/Listener/UpdateMentionsMetadataWhenVisible.php
@@ -9,6 +9,7 @@
 
 namespace Flarum\Mentions\Listener;
 
+use Flarum\Mentions\Notification\GroupMentionedBlueprint;
 use Flarum\Mentions\Notification\PostMentionedBlueprint;
 use Flarum\Mentions\Notification\UserMentionedBlueprint;
 use Flarum\Notification\NotificationSyncer;
@@ -50,6 +51,11 @@ class UpdateMentionsMetadataWhenVisible
             $event->post,
             Utils::getAttributeValues($content, 'POSTMENTION', 'id')
         );
+
+        $this->syncGroupMentions(
+            $event->post,
+            Utils::getAttributeValues($content, 'GROUPMENTION', 'id')
+        );
     }
 
     protected function syncUserMentions(Post $post, array $mentioned)
@@ -84,4 +90,21 @@ class UpdateMentionsMetadataWhenVisible
             $this->notifications->sync(new PostMentionedBlueprint($post, $reply), [$post->user]);
         }
     }
+
+    protected function syncGroupMentions(Post $post, array $mentioned)
+    {
+        $post->mentionsGroups()->sync($mentioned);
+        $post->unsetRelation('mentionsGroups');
+
+        $users = User::whereHas('groups', function ($query) use ($mentioned) {
+            $query->whereIn('id', $mentioned);
+        })
+            ->get()
+            ->filter(function (User $user) use ($post) {
+                return $post->isVisibleTo($user) && $user->id !== $post->user_id;
+            })
+            ->all();
+
+        $this->notifications->sync(new GroupMentionedBlueprint($post), $users);
+    }
 }
diff --git a/extensions/mentions/src/Notification/GroupMentionedBlueprint.php b/extensions/mentions/src/Notification/GroupMentionedBlueprint.php
new file mode 100644
index 000000000..1842d0e24
--- /dev/null
+++ b/extensions/mentions/src/Notification/GroupMentionedBlueprint.php
@@ -0,0 +1,89 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Mentions\Notification;
+
+use Flarum\Notification\Blueprint\BlueprintInterface;
+use Flarum\Notification\MailableInterface;
+use Flarum\Post\Post;
+use Symfony\Contracts\Translation\TranslatorInterface;
+
+class GroupMentionedBlueprint implements BlueprintInterface, MailableInterface
+{
+    /**
+     * @var Post
+     */
+    public $post;
+
+    /**
+     * @param Post $post
+     */
+    public function __construct(Post $post)
+    {
+        $this->post = $post;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSubject()
+    {
+        return $this->post;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getFromUser()
+    {
+        return $this->post->user;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getData()
+    {
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getEmailView()
+    {
+        return ['text' => 'flarum-mentions::emails.groupMentioned'];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getEmailSubject(TranslatorInterface $translator)
+    {
+        return $translator->trans('flarum-mentions.email.group_mentioned.subject', [
+            '{mentioner_display_name}' => $this->post->user->display_name,
+            '{title}' => $this->post->discussion->title
+        ]);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getType()
+    {
+        return 'groupMentioned';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getSubjectModel()
+    {
+        return Post::class;
+    }
+}
diff --git a/extensions/mentions/tests/integration/api/GroupMentionsTest.php b/extensions/mentions/tests/integration/api/GroupMentionsTest.php
new file mode 100644
index 000000000..78ea3d50c
--- /dev/null
+++ b/extensions/mentions/tests/integration/api/GroupMentionsTest.php
@@ -0,0 +1,420 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Mentions\Tests\integration\api;
+
+use Carbon\Carbon;
+use Flarum\Group\Group;
+use Flarum\Post\CommentPost;
+use Flarum\Testing\integration\RetrievesAuthorizedUsers;
+use Flarum\Testing\integration\TestCase;
+use Flarum\User\User;
+
+class GroupMentionsTest extends TestCase
+{
+    use RetrievesAuthorizedUsers;
+
+    /**
+     * @inheritDoc
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->extension('flarum-mentions');
+
+        $this->prepareDatabase([
+            'users' => [
+                ['id' => 3, 'username' => 'potato', 'email' => 'potato@machine.local', 'is_email_confirmed' => 1],
+                ['id' => 4, 'username' => 'toby', 'email' => 'toby@machine.local', 'is_email_confirmed' => 1],
+                ['id' => 5, 'username' => 'bad_user', 'email' => 'bad_user@machine.local', 'is_email_confirmed' => 1],
+            ],
+            'discussions' => [
+                ['id' => 2, 'title' => __CLASS__, 'created_at' => Carbon::now(), 'last_posted_at' => Carbon::now(), 'user_id' => 3, 'first_post_id' => 4, 'comment_count' => 2],
+            ],
+            'posts' => [
+                ['id' => 4, 'number' => 2, 'discussion_id' => 2, 'created_at' => Carbon::now(), 'user_id' => 3, 'type' => 'comment', 'content' => '<r><p>One of the <GROUPMENTION color="#80349E" groupname="Mods" icon="fas fa-bolt" id="4">@"Mods"#g4</GROUPMENTION> will look at this</p></r>'],
+                ['id' => 6, 'number' => 3, 'discussion_id' => 2, 'created_at' => Carbon::now(), 'user_id' => 3, 'type' => 'comment', 'content' => '<r><p><GROUPMENTION color="#80349E" groupname="OldGroupName" icon="fas fa-circle" id="100">@"OldGroupName"#g100</GROUPMENTION></p></r>'],
+                ['id' => 7, 'number' => 4, 'discussion_id' => 2, 'created_at' => Carbon::now(), 'user_id' => 3, 'type' => 'comment', 'content' => '<r><p><GROUPMENTION color="#000" groupname="OldGroupName" icon="fas fa-circle" id="11">@"OldGroupName"#g11</GROUPMENTION></p></r>'],
+            ],
+            'post_mentions_group' => [
+                ['post_id' => 4, 'mentions_group_id' => 4],
+                ['post_id' => 7, 'mentions_group_id' => 11],
+            ],
+            'group_permission' => [
+                ['group_id' => Group::MEMBER_ID, 'permission' => 'postWithoutThrottle'],
+            ],
+            'groups' => [
+                [
+                    'id' => 10,
+                    'name_singular' => 'Hidden',
+                    'name_plural' => 'Ninjas',
+                    'color' => null,
+                    'icon' => 'fas fa-wrench',
+                    'is_hidden' => 1
+                ],
+                [
+                    'id' => 11,
+                    'name_singular' => 'Fresh Name',
+                    'name_plural' => 'Fresh Name',
+                    'color' => '#ccc',
+                    'icon' => 'fas fa-users',
+                    'is_hidden' => 0
+                ]
+            ]
+        ]);
+    }
+
+    /**
+     * @test
+     */
+    public function rendering_a_valid_group_mention_works()
+    {
+        $response = $this->send(
+            $this->request('GET', '/api/posts/4')
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('<p>One of the <span style="background:#80349E" class="GroupMention">@Mods<i class="icon fas fa-bolt"></i></span> will look at this</p>', $response['data']['attributes']['contentHtml']);
+        $this->assertNotNull(CommentPost::find($response['data']['id'])->mentionsGroups->find(4));
+    }
+
+    /**
+     * @test
+     */
+    public function mentioning_an_invalid_group_doesnt_work()
+    {
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 1,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"InvalidGroup"#g99',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ]
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@"InvalidGroup"#g99', $response['data']['attributes']['content']);
+        $this->assertStringNotContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(0, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function deleted_group_mentions_render_with_deleted_label()
+    {
+        $deleted_text = $this->app()->getContainer()->make('translator')->trans('flarum-mentions.forum.group_mention.deleted_text');
+
+        $response = $this->send(
+            $this->request('GET', '/api/posts/6', [
+                'authenticatedAs' => 1,
+            ])
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString("@$deleted_text", $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('GroupMention--deleted', $response['data']['attributes']['contentHtml']);
+        $this->assertStringNotContainsString('@OldGroupName', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(0, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function group_mentions_render_with_fresh_data()
+    {
+        $response = $this->send(
+            $this->request('GET', '/api/posts/7', [
+                'authenticatedAs' => 1,
+            ])
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@Fresh Name', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertStringNotContainsString('@OldGroupName', $response['data']['attributes']['contentHtml']);
+        $this->assertNotNull(CommentPost::find($response['data']['id'])->mentionsGroups->find(11));
+    }
+
+    /**
+     * @test
+     */
+    public function mentioning_a_group_as_an_admin_user_works()
+    {
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 1,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Mods"#g4',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ]
+                    ]
+                ]
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@Mods', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('fas fa-bolt', $response['data']['attributes']['contentHtml']);
+        $this->assertEquals('@"Mods"#g4', $response['data']['attributes']['content']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(1, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function mentioning_multiple_groups_as_an_admin_user_works()
+    {
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 1,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Admins"#g1 @"Mods"#g4',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ]
+                    ]
+                ]
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@Admins', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('@Mods', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('fas fa-wrench', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('fas fa-bolt', $response['data']['attributes']['contentHtml']);
+        $this->assertEquals('@"Admins"#g1 @"Mods"#g4', $response['data']['attributes']['content']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(2, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function mentioning_a_virtual_group_as_an_admin_user_does_not_work()
+    {
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 1,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Members"#g3 @"Guests"#g2',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ]
+                    ]
+                ]
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringNotContainsString('@Members', $response['data']['attributes']['contentHtml']);
+        $this->assertStringNotContainsString('@Guests', $response['data']['attributes']['contentHtml']);
+        $this->assertEquals('@"Members"#g3 @"Guests"#g2', $response['data']['attributes']['content']);
+        $this->assertStringNotContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(0, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function regular_user_does_not_have_group_mention_permission_by_default()
+    {
+        $this->database();
+        $this->assertFalse(User::find(3)->can('mentionGroups'));
+    }
+
+    /**
+     * @test
+     */
+    public function regular_user_does_have_group_mention_permission_when_added()
+    {
+        $this->prepareDatabase([
+            'group_permission' => [
+                ['group_id' => Group::MEMBER_ID, 'permission' => 'mentionGroups'],
+            ]
+        ]);
+
+        $this->database();
+        $this->assertTrue(User::find(3)->can('mentionGroups'));
+    }
+
+    /**
+     * @test
+     */
+    public function user_without_permission_cannot_mention_groups()
+    {
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 3,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Mods"#g4',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ],
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringNotContainsString('@Mods', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('@"Mods"#g4', $response['data']['attributes']['content']);
+        $this->assertStringNotContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(0, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function user_with_permission_can_mention_groups()
+    {
+        $this->prepareDatabase([
+            'group_permission' => [
+                ['group_id' => Group::MEMBER_ID, 'permission' => 'mentionGroups'],
+            ]
+        ]);
+
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 3,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Mods"#g4',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ],
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@Mods', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('@"Mods"#g4', $response['data']['attributes']['content']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(1, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function user_with_permission_cannot_mention_hidden_groups()
+    {
+        $this->prepareDatabase([
+            'group_permission' => [
+                ['group_id' => Group::MEMBER_ID, 'permission' => 'mentionGroups'],
+            ]
+        ]);
+
+        $response = $this->send(
+            $this->request('POST', '/api/posts', [
+                'authenticatedAs' => 3,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => '@"Ninjas"#g10',
+                        ],
+                        'relationships' => [
+                            'discussion' => ['data' => ['id' => 2]],
+                        ],
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(201, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringNotContainsString('@Ninjas', $response['data']['attributes']['contentHtml']);
+        $this->assertStringContainsString('@"Ninjas"#g10', $response['data']['attributes']['content']);
+        $this->assertStringNotContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertCount(0, CommentPost::find($response['data']['id'])->mentionsGroups);
+    }
+
+    /**
+     * @test
+     */
+    public function editing_a_post_that_has_a_mention_works()
+    {
+        $response = $this->send(
+            $this->request('PATCH', '/api/posts/4', [
+                'authenticatedAs' => 1,
+                'json' => [
+                    'data' => [
+                        'attributes' => [
+                            'content' => 'New content with @"Mods"#g4 mention',
+                        ],
+                    ],
+                ],
+            ])
+        );
+
+        $this->assertEquals(200, $response->getStatusCode());
+
+        $response = json_decode($response->getBody(), true);
+
+        $this->assertStringContainsString('@Mods', $response['data']['attributes']['contentHtml']);
+        $this->assertEquals('New content with @"Mods"#g4 mention', $response['data']['attributes']['content']);
+        $this->assertStringContainsString('GroupMention', $response['data']['attributes']['contentHtml']);
+        $this->assertNotNull(CommentPost::find($response['data']['id'])->mentionsGroups->find(4));
+    }
+}
diff --git a/extensions/mentions/views/emails/groupMentioned.blade.php b/extensions/mentions/views/emails/groupMentioned.blade.php
new file mode 100644
index 000000000..52b6f0458
--- /dev/null
+++ b/extensions/mentions/views/emails/groupMentioned.blade.php
@@ -0,0 +1,7 @@
+{!! $translator->trans('flarum-mentions.email.group_mentioned.body', [
+'{recipient_display_name}' => $user->display_name,
+'{mentioner_display_name}' => $blueprint->post->user->display_name,
+'{title}' => $blueprint->post->discussion->title,
+'{url}' => $url->to('forum')->route('discussion', ['id' => $blueprint->post->discussion_id, 'near' => $blueprint->post->number]),
+'{content}' => $blueprint->post->content
+]) !!}
diff --git a/framework/core/src/Extend/Formatter.php b/framework/core/src/Extend/Formatter.php
index 0eb79a9ff..75f7f5418 100644
--- a/framework/core/src/Extend/Formatter.php
+++ b/framework/core/src/Extend/Formatter.php
@@ -52,6 +52,7 @@ class Formatter implements ExtenderInterface, LifecycleInterface
      * - \s9e\TextFormatter\Parser $parser
      * - mixed $context
      * - string $text: The text to be parsed.
+     * - \Flarum\User\User|null $actor. This argument MUST either be nullable, or omitted entirely.
      *
      * The callback should return:
      * - string $text: The text to be parsed.
diff --git a/framework/core/src/Formatter/Formatter.php b/framework/core/src/Formatter/Formatter.php
index 46958d0e9..2db336cd2 100644
--- a/framework/core/src/Formatter/Formatter.php
+++ b/framework/core/src/Formatter/Formatter.php
@@ -9,6 +9,7 @@
 
 namespace Flarum\Formatter;
 
+use Flarum\User\User;
 use Illuminate\Contracts\Cache\Repository;
 use Psr\Http\Message\ServerRequestInterface;
 use s9e\TextFormatter\Configurator;
@@ -83,14 +84,15 @@ class Formatter
      *
      * @param string $text
      * @param mixed $context
+     * @param User|null $user
      * @return string
      */
-    public function parse($text, $context = null)
+    public function parse($text, $context = null, User $user = null)
     {
         $parser = $this->getParser($context);
 
         foreach ($this->parsingCallbacks as $callback) {
-            $text = $callback($parser, $context, $text);
+            $text = $callback($parser, $context, $text, $user);
         }
 
         return $parser->parse($text);
diff --git a/framework/core/src/Post/Command/PostReplyHandler.php b/framework/core/src/Post/Command/PostReplyHandler.php
index 96de698d0..b0bfb8877 100644
--- a/framework/core/src/Post/Command/PostReplyHandler.php
+++ b/framework/core/src/Post/Command/PostReplyHandler.php
@@ -85,7 +85,8 @@ class PostReplyHandler
             $discussion->id,
             Arr::get($command->data, 'attributes.content'),
             $actor->id,
-            $command->ipAddress
+            $command->ipAddress,
+            $command->actor,
         );
 
         if ($actor->isAdmin() && ($time = Arr::get($command->data, 'attributes.createdAt'))) {
diff --git a/framework/core/src/Post/CommentPost.php b/framework/core/src/Post/CommentPost.php
index 6e89e79ea..7455abc12 100644
--- a/framework/core/src/Post/CommentPost.php
+++ b/framework/core/src/Post/CommentPost.php
@@ -44,9 +44,10 @@ class CommentPost extends Post
      * @param string $content
      * @param int $userId
      * @param string $ipAddress
+     * @param User|null $actor
      * @return static
      */
-    public static function reply($discussionId, $content, $userId, $ipAddress)
+    public static function reply($discussionId, $content, $userId, $ipAddress, User $actor = null)
     {
         $post = new static;
 
@@ -57,7 +58,7 @@ class CommentPost extends Post
         $post->ip_address = $ipAddress;
 
         // Set content last, as the parsing may rely on other post attributes.
-        $post->content = $content;
+        $post->setContentAttribute($content, $actor);
 
         $post->raise(new Posted($post));
 
@@ -74,7 +75,7 @@ class CommentPost extends Post
     public function revise($content, User $actor)
     {
         if ($this->content !== $content) {
-            $this->content = $content;
+            $this->setContentAttribute($content, $actor);
 
             $this->edited_at = Carbon::now();
             $this->edited_user_id = $actor->id;
@@ -145,10 +146,11 @@ class CommentPost extends Post
      * Parse the content before it is saved to the database.
      *
      * @param string $value
+     * @param User $actor
      */
-    public function setContentAttribute($value)
+    public function setContentAttribute($value, User $actor = null)
     {
-        $this->attributes['content'] = $value ? static::$formatter->parse($value, $this) : null;
+        $this->attributes['content'] = $value ? static::$formatter->parse($value, $this, $actor ?? $this->user) : null;
     }
 
     /**