diff --git a/changelogs/fragments/11443-fix-keycloak-client-diff-for-null-attributes.yml b/changelogs/fragments/11443-fix-keycloak-client-diff-for-null-attributes.yml
new file mode 100644
index 0000000000..a28a98e3f1
--- /dev/null
+++ b/changelogs/fragments/11443-fix-keycloak-client-diff-for-null-attributes.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - keycloak_client - fix idempotency bug caused by ``null`` client attribute value differences for non-existing client attributes (https://github.com/ansible-collections/community.general/issues/11443, https://github.com/ansible-collections/community.general/pull/11444).
\ No newline at end of file
diff --git a/plugins/modules/keycloak_client.py b/plugins/modules/keycloak_client.py
index 0bdf3d853b..c05a595ac5 100644
--- a/plugins/modules/keycloak_client.py
+++ b/plugins/modules/keycloak_client.py
@@ -1319,7 +1319,11 @@ def main():
             new_param_value = flow_binding_from_dict_to_model(new_param_value, realm, kc)
         elif client_param == "attributes" and "attributes" in before_client:
             attributes_copy = copy.deepcopy(before_client["attributes"])
-            attributes_copy.update(new_param_value)
+            # Merge client attributes while excluding null-valued attributes that are not present in Keycloak's response.
+            # This ensures idempotency by treating absent attributes and null attributes as equivalent.
+            attributes_copy.update(
+                {key: value for key, value in new_param_value.items() if value is not None or key in attributes_copy}
+            )
             new_param_value = attributes_copy
         elif client_param in ["clientScopesBehavior", "client_scopes_behavior"]:
             continue