diff --git a/litellm/proxy/auth/user_api_key_auth.py b/litellm/proxy/auth/user_api_key_auth.py
index 61c618eeb18..ffca4d533be 100644
--- a/litellm/proxy/auth/user_api_key_auth.py
+++ b/litellm/proxy/auth/user_api_key_auth.py
@@ -807,6 +807,7 @@ async def _user_api_key_auth_builder(  # noqa: PLR0915
                             api_key=None,
                             user_role=LitellmUserRoles.PROXY_ADMIN,
                             user_id=user_id,
+                            key_alias=user_id,
                             team_id=team_id,
                             team_alias=(
                                 team_object.team_alias
@@ -826,6 +827,7 @@ async def _user_api_key_auth_builder(  # noqa: PLR0915
 
                     valid_token = UserAPIKeyAuth(
                         api_key=None,
+                        key_alias=user_id,
                         team_id=team_id,
                         team_alias=(
                             team_object.team_alias if team_object is not None else None
diff --git a/tests/test_litellm/proxy/auth/test_handle_jwt.py b/tests/test_litellm/proxy/auth/test_handle_jwt.py
index 5303da6fbcf..bd9fb517cdf 100644
--- a/tests/test_litellm/proxy/auth/test_handle_jwt.py
+++ b/tests/test_litellm/proxy/auth/test_handle_jwt.py
@@ -2029,3 +2029,184 @@ async def test_find_and_validate_specific_team_id_no_hint_for_valid_field():
 
     error_msg = str(exc_info.value)
     assert "Hint" not in error_msg
+
+
+@pytest.mark.asyncio
+async def test_jwt_auth_sets_key_alias_to_user_id_admin():
+    """
+    Verify that JWT standard auth populates key_alias with user_id
+    on the admin path so Prometheus api_key_alias label is non-empty.
+    """
+    import json
+
+    from starlette.datastructures import URL
+
+    import litellm
+    import litellm.proxy.proxy_server
+    from litellm.proxy.auth.user_api_key_auth import _user_api_key_auth_builder
+    from litellm.proxy.utils import ProxyLogging
+    from litellm.caching.dual_cache import DualCache
+
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
+
+    jwt_handler = JWTHandler()
+    jwt_handler.litellm_jwtauth = LiteLLM_JWTAuth()
+
+    # Wire proxy server globals
+    setattr(litellm.proxy.proxy_server, "premium_user", True)
+    setattr(litellm.proxy.proxy_server, "general_settings", {"enable_jwt_auth": True})
+    setattr(litellm.proxy.proxy_server, "jwt_handler", jwt_handler)
+    setattr(litellm.proxy.proxy_server, "prisma_client", None)
+    setattr(litellm.proxy.proxy_server, "master_key", None)
+    setattr(litellm.proxy.proxy_server, "llm_router", None)
+    setattr(litellm.proxy.proxy_server, "llm_model_list", None)
+    setattr(litellm.proxy.proxy_server, "proxy_logging_obj", proxy_logging_obj)
+    setattr(litellm.proxy.proxy_server, "open_telemetry_logger", None)
+    setattr(litellm.proxy.proxy_server, "model_max_budget_limiter", None)
+    setattr(litellm.proxy.proxy_server, "litellm_proxy_admin_name", "admin")
+
+    auth_builder_result = {
+        "is_proxy_admin": True,
+        "team_id": "team_123",
+        "team_object": LiteLLM_TeamTable(team_id="team_123"),
+        "user_id": "test_user_1",
+        "user_object": LiteLLM_UserTable(
+            user_id="test_user_1", user_role=LitellmUserRoles.PROXY_ADMIN
+        ),
+        "end_user_id": None,
+        "end_user_object": None,
+        "org_id": None,
+        "token": "fake_jwt_token",
+        "team_membership": None,
+        "jwt_claims": {"sub": "test_user_1"},
+    }
+
+    from fastapi import Request
+
+    request = Request(scope={"type": "http", "headers": []})
+    request._url = URL(url="/chat/completions")
+
+    async def return_body():
+        return json.dumps({"model": "gpt-4"}).encode("utf-8")
+
+    request.body = return_body
+
+    with patch.object(
+        jwt_handler, "is_jwt", return_value=True
+    ), patch.object(
+        JWTAuthManager,
+        "auth_builder",
+        new_callable=AsyncMock,
+        return_value=auth_builder_result,
+    ), patch(
+        "litellm.proxy.auth.user_api_key_auth.get_global_proxy_spend",
+        new_callable=AsyncMock,
+        return_value=0.0,
+    ):
+        result = await _user_api_key_auth_builder(
+            request=request,
+            api_key="Bearer fake_jwt_token",
+            azure_api_key_header="",
+            anthropic_api_key_header=None,
+            google_ai_studio_api_key_header=None,
+            azure_apim_header=None,
+            request_data={"model": "gpt-4"},
+        )
+
+        assert result.key_alias == "test_user_1"
+        assert result.user_id == "test_user_1"
+        assert result.user_role == LitellmUserRoles.PROXY_ADMIN
+
+
+@pytest.mark.asyncio
+async def test_jwt_auth_sets_key_alias_to_user_id_non_admin():
+    """
+    Verify that JWT standard auth populates key_alias with user_id
+    on the non-admin path so Prometheus api_key_alias label is non-empty.
+    """
+    import json
+
+    from starlette.datastructures import URL
+
+    import litellm
+    import litellm.proxy.proxy_server
+    from litellm.proxy.auth.user_api_key_auth import _user_api_key_auth_builder
+    from litellm.proxy.utils import ProxyLogging
+    from litellm.caching.dual_cache import DualCache
+
+    proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
+
+    jwt_handler = JWTHandler()
+    jwt_handler.litellm_jwtauth = LiteLLM_JWTAuth()
+
+    # Wire proxy server globals
+    setattr(litellm.proxy.proxy_server, "premium_user", True)
+    setattr(litellm.proxy.proxy_server, "general_settings", {"enable_jwt_auth": True})
+    setattr(litellm.proxy.proxy_server, "jwt_handler", jwt_handler)
+    setattr(litellm.proxy.proxy_server, "prisma_client", None)
+    setattr(litellm.proxy.proxy_server, "master_key", None)
+    setattr(litellm.proxy.proxy_server, "llm_router", None)
+    setattr(litellm.proxy.proxy_server, "llm_model_list", None)
+    setattr(litellm.proxy.proxy_server, "proxy_logging_obj", proxy_logging_obj)
+    setattr(litellm.proxy.proxy_server, "open_telemetry_logger", None)
+    setattr(litellm.proxy.proxy_server, "model_max_budget_limiter", None)
+    setattr(litellm.proxy.proxy_server, "litellm_proxy_admin_name", "admin")
+
+    team_object = LiteLLM_TeamTable(team_id="team_123")
+    user_object = LiteLLM_UserTable(
+        user_id="test_user_1", user_role=LitellmUserRoles.INTERNAL_USER
+    )
+
+    auth_builder_result = {
+        "is_proxy_admin": False,
+        "team_id": "team_123",
+        "team_object": team_object,
+        "user_id": "test_user_1",
+        "user_object": user_object,
+        "end_user_id": None,
+        "end_user_object": None,
+        "org_id": None,
+        "token": "fake_jwt_token",
+        "team_membership": None,
+        "jwt_claims": {"sub": "test_user_1"},
+    }
+
+    from fastapi import Request
+
+    request = Request(scope={"type": "http", "headers": []})
+    request._url = URL(url="/chat/completions")
+
+    async def return_body():
+        return json.dumps({"model": "gpt-4"}).encode("utf-8")
+
+    request.body = return_body
+
+    with patch.object(
+        jwt_handler, "is_jwt", return_value=True
+    ), patch.object(
+        JWTAuthManager,
+        "auth_builder",
+        new_callable=AsyncMock,
+        return_value=auth_builder_result,
+    ), patch(
+        "litellm.proxy.auth.user_api_key_auth.get_global_proxy_spend",
+        new_callable=AsyncMock,
+        return_value=0.0,
+    ), patch(
+        "litellm.proxy.auth.user_api_key_auth.common_checks",
+        new_callable=AsyncMock,
+        return_value=True,
+    ):
+        result = await _user_api_key_auth_builder(
+            request=request,
+            api_key="Bearer fake_jwt_token",
+            azure_api_key_header="",
+            anthropic_api_key_header=None,
+            google_ai_studio_api_key_header=None,
+            azure_apim_header=None,
+            request_data={"model": "gpt-4"},
+        )
+
+        assert result.key_alias == "test_user_1"
+        assert result.user_id == "test_user_1"
+        assert result.user_role == LitellmUserRoles.INTERNAL_USER