diff --git a/api/python/tests/test_entities.py b/api/python/tests/test_entities.py
new file mode 100644
index 00000000..0ccdbc82
--- /dev/null
+++ b/api/python/tests/test_entities.py
@@ -0,0 +1,16 @@
+from cellxgene_ontology_guide.entities import Ontology
+from cellxgene_ontology_guide.supported_versions import load_supported_versions
+
+
+def test_all_supported_ontologies_in_dataclass():
+    """
+    Test that all supported ontologies are defined in the Ontology enum (and deprecated ontologies removed).
+    Do not include additional ontologies.
+    """
+    ontology_info = load_supported_versions()
+    supported_ontologies = set()
+    for _, version_info in ontology_info.items():
+        for ontology, _ in version_info["ontologies"].items():
+            supported_ontologies.add(ontology)
+
+    assert supported_ontologies == {ontology.name for ontology in Ontology}