diff --git a/.chronus/changes/python-api-version-override-2026-09-18-02-03-00.md b/.chronus/changes/python-api-version-override-2026-09-18-02-03-00.md
new file mode 100644
index 00000000000..cb55a7412e6
--- /dev/null
+++ b/.chronus/changes/python-api-version-override-2026-09-18-02-03-00.md
@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+Add mock API coverage for Azure Core child-client API-version overrides.
diff --git a/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_core_api_version_override_async.py b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_core_api_version_override_async.py
new file mode 100644
index 00000000000..317f55bb35c
--- /dev/null
+++ b/packages/http-client-python/tests/mock_api/azure/asynctests/test_azure_core_api_version_override_async.py
@@ -0,0 +1,19 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+import pytest_asyncio
+from specs.azure.core.apiversionoverride.aio import ApiVersionOverrideClient
+
+
+@pytest_asyncio.fixture
+async def client():
+    async with ApiVersionOverrideClient() as client:
+        yield client
+
+
+@pytest.mark.asyncio
+async def test_legacy_client_api_version_override(client: ApiVersionOverrideClient):
+    await client.legacy_client.get()
diff --git a/packages/http-client-python/tests/mock_api/azure/test_azure_core_api_version_override.py b/packages/http-client-python/tests/mock_api/azure/test_azure_core_api_version_override.py
new file mode 100644
index 00000000000..96bdaa840b3
--- /dev/null
+++ b/packages/http-client-python/tests/mock_api/azure/test_azure_core_api_version_override.py
@@ -0,0 +1,17 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+from specs.azure.core.apiversionoverride import ApiVersionOverrideClient
+
+
+@pytest.fixture
+def client():
+    with ApiVersionOverrideClient() as client:
+        yield client
+
+
+def test_legacy_client_api_version_override(client: ApiVersionOverrideClient):
+    client.legacy_client.get()