diff --git a/netbox/circuits/api/serializers_/circuits.py b/netbox/circuits/api/serializers_/circuits.py
index 33d0e54a1..7b444cd87 100644
--- a/netbox/circuits/api/serializers_/circuits.py
+++ b/netbox/circuits/api/serializers_/circuits.py
@@ -80,14 +80,16 @@ class CircuitTerminationSerializer(NetBoxModelSerializer, CabledObjectSerializer
 
 
 class CircuitGroupSerializer(NetBoxModelSerializer):
+    # Related object counts
+    circuit_group_assignment_count = RelatedObjectCountField('circuit_group_assignments')
 
     class Meta:
         model = CircuitGroup
         fields = [
             'id', 'url', 'display_url', 'display', 'name', 'slug', 'description', 'tenant',
-            'tags', 'custom_fields', 'created', 'last_updated',
+            'tags', 'custom_fields', 'created', 'last_updated', 'circuit_group_assignment_count'
         ]
-        brief_fields = ('id', 'url', 'display', 'name', 'slug', 'description')
+        brief_fields = ('id', 'url', 'display', 'name', 'slug', 'description', 'circuit_group_assignment_count')
 
 
 class CircuitGroupAssignmentSerializer(NetBoxModelSerializer):
diff --git a/netbox/circuits/tests/test_api.py b/netbox/circuits/tests/test_api.py
index b6e42b7aa..41f621cf8 100644
--- a/netbox/circuits/tests/test_api.py
+++ b/netbox/circuits/tests/test_api.py
@@ -208,7 +208,7 @@ class CircuitTerminationTest(APIViewTestCases.APIViewTestCase):
 
 class CircuitGroupTest(APIViewTestCases.APIViewTestCase):
     model = CircuitGroup
-    brief_fields = ['description', 'display', 'id', 'name', 'slug', 'url']
+    brief_fields = ['circuit_group_assignment_count', 'description', 'display', 'id', 'name', 'slug', 'url']
     bulk_update_data = {
         'description': 'New description',
     }