diff --git a/app/assets/javascripts/discourse/components/composer-editor.js.es6 b/app/assets/javascripts/discourse/components/composer-editor.js.es6
index 3d25c3a4f35..29e2d313aa9 100644
--- a/app/assets/javascripts/discourse/components/composer-editor.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-editor.js.es6
@@ -77,16 +77,18 @@ export default Ember.Component.extend({
     const $input = this.$('.d-editor-input');
     const $preview = this.$('.d-editor-preview-wrapper');
 
-    $input.autocomplete({
-      template: findRawTemplate('user-selector-autocomplete'),
-      dataSource: term => userSearch({
-        term,
-        topicId,
-        includeMentionableGroups: true
-      }),
-      key: "@",
-      transformComplete: v => v.username || v.name
-    });
+    if (this.siteSettings.enable_mentions) {
+      $input.autocomplete({
+        template: findRawTemplate('user-selector-autocomplete'),
+        dataSource: term => userSearch({
+          term,
+          topicId,
+          includeMentionableGroups: true
+        }),
+        key: "@",
+        transformComplete: v => v.username || v.name
+      });
+    }
 
     if (this._enableAdvancedEditorPreviewSync()) {
       this._initInputPreviewSync($input, $preview);
diff --git a/app/assets/javascripts/discourse/lib/search.js.es6 b/app/assets/javascripts/discourse/lib/search.js.es6
index 266f374a65d..f64b74db943 100644
--- a/app/assets/javascripts/discourse/lib/search.js.es6
+++ b/app/assets/javascripts/discourse/lib/search.js.es6
@@ -154,13 +154,15 @@ export function applySearchAutocomplete($input, siteSettings, appEvents, options
     afterComplete
   }, options));
 
-  $input.autocomplete(_.merge({
-    template: findRawTemplate('user-selector-autocomplete'),
-    key: "@",
-    width: '100%',
-    treatAsTextarea: true,
-    transformComplete: v => v.username || v.name,
-    dataSource: term => userSearch({ term, includeGroups: true }),
-    afterComplete
-  }, options));
+  if (Discourse.SiteSettings.enable_mentions) {
+    $input.autocomplete(_.merge({
+      template: findRawTemplate('user-selector-autocomplete'),
+      key: "@",
+      width: '100%',
+      treatAsTextarea: true,
+      transformComplete: v => v.username || v.name,
+      dataSource: term => userSearch({ term, includeGroups: true }),
+      afterComplete
+    }, options));
+  }
 };
diff --git a/app/assets/javascripts/pretty-text/engines/discourse-markdown/mentions.js.es6 b/app/assets/javascripts/pretty-text/engines/discourse-markdown/mentions.js.es6
index 7314bc1f98d..8484f7ba6c0 100644
--- a/app/assets/javascripts/pretty-text/engines/discourse-markdown/mentions.js.es6
+++ b/app/assets/javascripts/pretty-text/engines/discourse-markdown/mentions.js.es6
@@ -38,6 +38,10 @@ function addMention(buffer, matches, state) {
 }
 
 export function setup(helper) {
+  helper.registerOptions((opts, siteSettings) => {
+    opts.features.mentions = !!siteSettings.enable_mentions;
+  });
+
   helper.registerPlugin(md => {
 
     const rule = {
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 07c38b521ff..7bb5823f9e5 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1283,6 +1283,7 @@ en:
     newuser_max_replies_per_topic: "Maximum number of replies a new user can make in a single topic until someone replies to them."
     max_mentions_per_post: "Maximum number of @name notifications anyone can use in a post."
     max_users_notified_per_group_mention: "Maximum number of users that may receive a notification if a group is mentioned (if threshold is met no notifications will be raised)"
+    enable_mentions: "Allow users to mention other users."
 
     create_thumbnails: "Create thumbnails and lightbox images that are too large to fit in a post."
 
diff --git a/config/site_settings.yml b/config/site_settings.yml
index 38c102a19f6..3d004c32674 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -537,6 +537,9 @@ posting:
     default: 1
     client: true
   post_undo_action_window_mins: 10
+  enable_mentions:
+    default: true
+    client: true
   max_mentions_per_post: 10
   max_users_notified_per_group_mention: 100
   newuser_max_replies_per_topic: 3
diff --git a/test/javascripts/lib/pretty-text-test.js.es6 b/test/javascripts/lib/pretty-text-test.js.es6
index f68de877be8..65803e8b188 100644
--- a/test/javascripts/lib/pretty-text-test.js.es6
+++ b/test/javascripts/lib/pretty-text-test.js.es6
@@ -8,6 +8,7 @@ QUnit.module("lib:pretty-text");
 const rawOpts = {
   siteSettings: {
     enable_emoji: true,
+    enable_mentions: true,
     emoji_set: 'emoji_one',
     highlighted_languages: 'json|ruby|javascript',
     default_code_lang: 'auto',
@@ -282,7 +283,6 @@ QUnit.test("Quotes", assert => {
 });
 
 QUnit.test("Mentions", assert => {
-
   const alwaysTrue = { mentionLookup: (function() { return "user"; }) };
 
   assert.cookedOptions("Hello @sam", alwaysTrue,
@@ -370,6 +370,12 @@ QUnit.test("Mentions", assert => {
                 "it allows mentions within HTML tags");
 });
 
+QUnit.test("Mentions - disabled", assert => {
+  assert.cookedOptions("@eviltrout",
+                { siteSettings : { enable_mentions: false }},
+                "<p>@eviltrout</p>");
+});
+
 QUnit.test("Category hashtags", assert => {
   const alwaysTrue = { categoryHashtagLookup: (function() { return ["http://test.discourse.org/category-hashtag", "category-hashtag"]; }) };