feast-dev
@@ -2341,7 +2341,7 @@ def _materialize_odfv(
         }
 
         for source_fv in source_fvs:
-            all_join_keys.update(source_fv.entities)
+            all_join_keys.update(source_fv.join_keys)
             if source_fv.batch_source:
                 entity_timestamp_col_names.add(source_fv.batch_source.timestamp_field)
 
@@ -2381,7 +2381,7 @@ def _materialize_odfv(
             job = provider.offline_store.pull_latest_from_table_or_query(
                 config=self.config,
                 data_source=source_fv.batch_source,
-                join_key_columns=source_fv.entities,
+                join_key_columns=source_fv.join_keys,
                 feature_name_columns=[f.name for f in source_fv.features],
                 timestamp_field=source_fv.batch_source.timestamp_field,
                 created_timestamp_column=getattr(

@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from tempfile import mkstemp
 from unittest.mock import AsyncMock, Mock, patch
 
@@ -19,11 +19,13 @@
 from feast.infra.offline_stores.file_source import FileSource
 from feast.infra.online_stores.dynamodb import DynamoDBOnlineStore
 from feast.infra.online_stores.sqlite import SqliteOnlineStoreConfig
+from feast.on_demand_feature_view import OnDemandFeatureView
 from feast.permissions.action import AuthzedAction
 from feast.permissions.permission import Permission
 from feast.permissions.policy import RoleBasedPolicy
 from feast.repo_config import RegistryConfig, RepoConfig
 from feast.stream_feature_view import stream_feature_view
+from feast.transformation.pandas_transformation import PandasTransformation
 from feast.types import Array, Bytes, Float32, Int64, String, ValueType, from_value_type
 from tests.universal.feature_repos.universal.feature_views import TAGS
 from tests.utils.cli_repo_creator import CliRunner, get_example_repo
@@ -511,6 +513,69 @@ def test_reapply_feature_view(test_feature_store, dataframe_source):
         test_feature_store.teardown()
 
 
+@pytest.mark.parametrize(
+    "test_feature_store",
+    [lazy_fixture("feature_store_with_local_registry")],
+)
+@pytest.mark.parametrize("dataframe_source", [lazy_fixture("simple_dataset_1")])
+def test_materialize_incremental_odfv_entity_name_differs_from_join_key(
+    test_feature_store, dataframe_source
+):
+    """Regression test for https://github.com/feast-dev/feast/issues/5965.
+
+    _materialize_odfv must resolve source feature views' join key *columns*
+    (FeatureView.join_keys), not their entity *names* (FeatureView.entities),
+    when building the entity_df and querying the offline store. Before the
+    fix, this failed whenever an Entity's name differed from its join_keys.
+    """
+    with prep_file_source(df=dataframe_source, timestamp_field="ts_1") as file_source:
+        # Entity name ("id") intentionally differs from its join key
+        # ("id_join_key"), mirroring the exact repro from the issue.
+        e = Entity(name="id", join_keys=["id_join_key"])
+
+        source_fv = FeatureView(
+            name="my_feature_view_1",
+            schema=[Field(name="float_col", dtype=Float32)],
+            entities=[e],
+            source=file_source,
+            ttl=timedelta(days=3650),
+        )
+
+        def transform(features_df: pd.DataFrame) -> pd.DataFrame:
+            out = pd.DataFrame()
+            out["label"] = features_df["float_col"].apply(
+                lambda v: "high" if v >= 1 else "low"
+            )
+            return out
+
+        odfv = OnDemandFeatureView(
+            name="my_odfv",
+            entities=[e],
+            sources=[source_fv],
+            schema=[Field(name="label", dtype=String)],
+            feature_transformation=PandasTransformation(
+                udf=transform, udf_string="transform"
+            ),
+            write_to_online_store=True,
+        )
+
+        test_feature_store.apply([e, source_fv, odfv])
+
+        # Should not raise. Before the fix, this raised
+        # FeastJoinKeysDuringMaterialization because _materialize_odfv
+        # queried the offline store for a column named "id" (the entity
+        # name) instead of "id_join_key" (the actual join key column).
+        test_feature_store.materialize_incremental(end_date=datetime.now(timezone.utc))
+
+        response = test_feature_store.get_online_features(
+            features=["my_odfv:label"],
+            entity_rows=[{"id_join_key": 1}],
+        ).to_dict()
+        assert response["label"][0] is not None
+
+        test_feature_store.teardown()
+
+
 def test_apply_conflicting_feature_view_names(feature_store_with_local_registry):
     """Test applying feature views with non-case-insensitively unique names"""
     driver = Entity(name="driver", join_keys=["driver_id"])