diff --git a/src/database/datasets.py b/src/database/datasets.py
index f69a035a..e1626e74 100644
--- a/src/database/datasets.py
+++ b/src/database/datasets.py
@@ -131,6 +131,25 @@ def get_features(dataset_id: int, connection: Connection) -> list[Feature]:
     return [Feature(**row, nominal_values=None) for row in rows.mappings()]
 
 
+def get_feature_ontologies(dataset_id: int, connection: Connection) -> dict[int, list[str]]:
+    """Return a mapping from feature index to its list of ontology URIs."""
+    rows = connection.execute(
+        text(
+            """
+            SELECT `index`, `value`
+            FROM data_feature_description
+            WHERE `did` = :dataset_id AND `description_type` = 'ontology'
+            ORDER BY `index`, `value`
+            """,
+        ),
+        parameters={"dataset_id": dataset_id},
+    )
+    ontologies: dict[int, list[str]] = {}
+    for row in rows.mappings():
+        ontologies.setdefault(row["index"], []).append(row["value"])
+    return ontologies
+
+
 def get_feature_values(dataset_id: int, *, feature_index: int, connection: Connection) -> list[str]:
     rows = connection.execute(
         text(
diff --git a/src/routers/openml/datasets.py b/src/routers/openml/datasets.py
index dda25117..df7c79c2 100644
--- a/src/routers/openml/datasets.py
+++ b/src/routers/openml/datasets.py
@@ -293,6 +293,9 @@ def get_dataset_features(
             feature_index=feature.index,
             connection=expdb,
         )
+    ontologies = database.datasets.get_feature_ontologies(dataset_id, expdb)
+    for feature in features:
+        feature.ontology = ontologies.get(feature.index)
 
     if not features:
         processing_state = database.datasets.get_latest_processing_update(dataset_id, expdb)
diff --git a/src/schemas/datasets/openml.py b/src/schemas/datasets/openml.py
index 8edb373c..997055b2 100644
--- a/src/schemas/datasets/openml.py
+++ b/src/schemas/datasets/openml.py
@@ -45,6 +45,7 @@ class Feature(BaseModel):
     is_row_identifier: bool
     number_of_missing_values: int
     nominal_values: list[str] | None
+    ontology: list[str] | None = None
 
 
 class EstimationProcedure(BaseModel):
diff --git a/tests/routers/openml/datasets_test.py b/tests/routers/openml/datasets_test.py
index 769e334a..8c596e65 100644
--- a/tests/routers/openml/datasets_test.py
+++ b/tests/routers/openml/datasets_test.py
@@ -158,6 +158,24 @@ def test_dataset_features(py_api: TestClient) -> None:
     ]
 
 
+def test_dataset_features_with_ontology(py_api: TestClient) -> None:
+    # Dataset 11 has ontology data for features 1, 2, and 3
+    response = py_api.get("/datasets/features/11")
+    assert response.status_code == HTTPStatus.OK
+    features = {f["index"]: f for f in response.json()}
+    assert features[1]["ontology"] == ["https://en.wikipedia.org/wiki/Service_(motor_vehicle)"]
+    assert features[2]["ontology"] == [
+        "https://en.wikipedia.org/wiki/Car_door",
+        "https://en.wikipedia.org/wiki/Door",
+    ]
+    assert features[3]["ontology"] == [
+        "https://en.wikipedia.org/wiki/Passenger_vehicles_in_the_United_States"
+    ]
+    # Features without ontology should not include the field
+    assert "ontology" not in features[0]
+    assert "ontology" not in features[4]
+
+
 def test_dataset_features_no_access(py_api: TestClient) -> None:
     response = py_api.get("/datasets/features/130")
     assert response.status_code == HTTPStatus.FORBIDDEN
diff --git a/tests/routers/openml/migration/datasets_migration_test.py b/tests/routers/openml/migration/datasets_migration_test.py
index 011d8dba..ddf60daf 100644
--- a/tests/routers/openml/migration/datasets_migration_test.py
+++ b/tests/routers/openml/migration/datasets_migration_test.py
@@ -222,10 +222,12 @@ def test_datasets_feature_is_identical(
                 values = feature.pop(key)
                 # The old API returns a str if there is only a single element
                 feature["nominal_value"] = values if len(values) > 1 else values[0]
+            elif key == "ontology":
+                # The old API returns a str if there is only a single element
+                values = feature.pop(key)
+                feature["ontology"] = values if len(values) > 1 else values[0]
             else:
                 # The old API formats bool as string in lower-case
                 feature[key] = str(value) if not isinstance(value, bool) else str(value).lower()
     original_features = original.json()["data_features"]["feature"]
-    for feature in original_features:
-        feature.pop("ontology", None)
     assert python_body == original_features