diff --git a/app/assets/stylesheets/framework/dropdowns.scss b/app/assets/stylesheets/framework/dropdowns.scss
index c0d8e6c328c..5c397470629 100644
--- a/app/assets/stylesheets/framework/dropdowns.scss
+++ b/app/assets/stylesheets/framework/dropdowns.scss
@@ -873,6 +873,13 @@
       min-width: 100%;
     }
   }
+
+  header.navbar-gitlab-new .header-content .dropdown {
+    .dropdown-menu {
+      left: 0;
+      min-width: 100%;
+    }
+  }
 }
 
 @include new-style-dropdown('.breadcrumbs-list .dropdown ');
diff --git a/changelogs/unreleased/38502-fix-nav-dropdown-close-animation.yml b/changelogs/unreleased/38502-fix-nav-dropdown-close-animation.yml
new file mode 100644
index 00000000000..974adb9ed28
--- /dev/null
+++ b/changelogs/unreleased/38502-fix-nav-dropdown-close-animation.yml
@@ -0,0 +1,5 @@
+---
+title: Fix navigation dropdown close animation on mobile screens
+merge_request: 14649
+author:
+type: fixed