diff --git a/litellm/proxy/management_endpoints/ui_sso.py b/litellm/proxy/management_endpoints/ui_sso.py
index dc128e88d51..e2216a911e1 100644
--- a/litellm/proxy/management_endpoints/ui_sso.py
+++ b/litellm/proxy/management_endpoints/ui_sso.py
@@ -1908,6 +1908,17 @@ async def auth_callback(request: Request, state: Optional[str] = None):
     """Verify login"""
     verbose_proxy_logger.info(f"Starting SSO callback with state: {state}")
 
+    oauth_error = request.query_params.get("error")
+    oauth_error_description = request.query_params.get("error_description")
+    if oauth_error:
+        oauth_error_detail = f"OAuth error: {oauth_error}"
+        if oauth_error_description:
+            oauth_error_detail += f", error_description: {oauth_error_description}"
+        raise HTTPException(
+            status_code=400,
+            detail=oauth_error_detail,
+        )
+
     # Check if this is a CLI login (state starts with our CLI prefix)
     from litellm.constants import LITELLM_CLI_SESSION_TOKEN_PREFIX
     from litellm.proxy._types import LiteLLM_JWTAuth
diff --git a/tests/test_litellm/proxy/management_endpoints/test_ui_sso.py b/tests/test_litellm/proxy/management_endpoints/test_ui_sso.py
index 976048b9521..3b123a80cd7 100644
--- a/tests/test_litellm/proxy/management_endpoints/test_ui_sso.py
+++ b/tests/test_litellm/proxy/management_endpoints/test_ui_sso.py
@@ -2711,6 +2711,7 @@ class TestCLIKeyRegenerationFlow:
 
         # Mock request
         mock_request = MagicMock(spec=Request)
+        mock_request.query_params = {}
 
         cli_state = f"{LITELLM_CLI_SESSION_TOKEN_PREFIX}:cli-new-session-key-456"
 
@@ -2784,6 +2785,26 @@ class TestCLIKeyRegenerationFlow:
                 received_response=None,
             )
 
+    @pytest.mark.asyncio
+    async def test_auth_callback_raises_on_oauth_error(self):
+        """Test that auth_callback returns a 401 when the provider redirects with an OAuth error"""
+        from litellm.proxy.management_endpoints.ui_sso import auth_callback
+
+        mock_request = MagicMock(spec=Request)
+        mock_request.query_params = {
+            "error": "access_denied",
+            "error_description": "User denied consent",
+        }
+
+        with pytest.raises(HTTPException) as exc_info:
+            await auth_callback(request=mock_request, state="test-state")
+
+        assert exc_info.value.status_code == 400
+        assert (
+            exc_info.value.detail
+            == "OAuth error: access_denied, error_description: User denied consent"
+        )
+
     def test_get_redirect_url_does_not_include_existing_key_in_url(self):
         """Test that redirect URL generation does NOT include existing_key in URL"""
         from litellm.proxy.management_endpoints.ui_sso import SSOAuthenticationHandler