diff --git a/src/registrar/admin.py b/src/registrar/admin.py
index 6585d602a..2f9bc97c5 100644
--- a/src/registrar/admin.py
+++ b/src/registrar/admin.py
@@ -322,7 +322,7 @@ class WebsiteAdmin(ListHeaderAdmin):
 
 
 class UserDomainRoleAdmin(ListHeaderAdmin):
-    """Custom domain role admin class."""
+    """Custom user domain role admin class."""
 
     # Columns
     list_display = [
@@ -340,6 +340,8 @@ class UserDomainRoleAdmin(ListHeaderAdmin):
     ]
     search_help_text = "Search by user, domain, or role."
 
+    autocomplete_fields = ["user", "domain"]
+
 
 class DomainInvitationAdmin(ListHeaderAdmin):
     """Custom domain invitation admin class."""
diff --git a/src/registrar/assets/sass/_theme/_admin.scss b/src/registrar/assets/sass/_theme/_admin.scss
index 56218c377..3afc81a35 100644
--- a/src/registrar/assets/sass/_theme/_admin.scss
+++ b/src/registrar/assets/sass/_theme/_admin.scss
@@ -245,3 +245,9 @@ h1, h2, h3 {
         padding-left: 90px;
     }
 }
+
+// Combo box
+#select2-id_domain-results,
+#select2-id_user-results {
+    width: 100%;
+}