diff --git a/litellm/proxy/ui_crud_endpoints/proxy_setting_endpoints.py b/litellm/proxy/ui_crud_endpoints/proxy_setting_endpoints.py
index 7ef6d6b67f..2f7f81a703 100644
--- a/litellm/proxy/ui_crud_endpoints/proxy_setting_endpoints.py
+++ b/litellm/proxy/ui_crud_endpoints/proxy_setting_endpoints.py
@@ -1061,13 +1061,26 @@ async def update_ui_settings(
             },
         )
 
-    settings_dict = settings.model_dump(exclude_none=True)
+    # Only include fields the caller actually sent (not Pydantic defaults).
+    settings_dict = settings.model_dump(exclude_unset=True)
 
     # Enforce allowlist and drop anything unexpected
-    ui_settings = {
+    incoming = {
         k: v for k, v in settings_dict.items() if k in ALLOWED_UI_SETTINGS_FIELDS
     }
 
+    # Merge with existing persisted settings so a partial PATCH doesn't
+    # overwrite fields the caller didn't send.
+    existing: dict = {}
+    db_existing = await prisma_client.db.litellm_uisettings.find_unique(
+        where={"id": "ui_settings"}
+    )
+    if db_existing and db_existing.ui_settings:
+        raw = db_existing.ui_settings
+        existing = json.loads(raw) if isinstance(raw, str) else dict(raw)
+
+    ui_settings = {**existing, **incoming}
+
     await prisma_client.db.litellm_uisettings.upsert(
         where={"id": "ui_settings"},
         data={
diff --git a/tests/test_litellm/proxy/ui_crud_endpoints/test_proxy_setting_endpoints.py b/tests/test_litellm/proxy/ui_crud_endpoints/test_proxy_setting_endpoints.py
index 31baab0092..f955a6134b 100644
--- a/tests/test_litellm/proxy/ui_crud_endpoints/test_proxy_setting_endpoints.py
+++ b/tests/test_litellm/proxy/ui_crud_endpoints/test_proxy_setting_endpoints.py
@@ -867,6 +867,7 @@ class TestProxySettingEndpoints:
         monkeypatch.setattr("litellm.proxy.proxy_server.store_model_in_db", True)
         mock_prisma = MagicMock()
         mock_prisma.db.litellm_uisettings.upsert = AsyncMock()
+        mock_prisma.db.litellm_uisettings.find_unique = AsyncMock(return_value=None)
         monkeypatch.setattr("litellm.proxy.proxy_server.prisma_client", mock_prisma)
 
         payload = {"disable_model_add_for_internal_users": True}
@@ -908,6 +909,7 @@ class TestProxySettingEndpoints:
         monkeypatch.setattr("litellm.proxy.proxy_server.store_model_in_db", True)
         mock_prisma = MagicMock()
         mock_prisma.db.litellm_uisettings.upsert = AsyncMock()
+        mock_prisma.db.litellm_uisettings.find_unique = AsyncMock(return_value=None)
         monkeypatch.setattr("litellm.proxy.proxy_server.prisma_client", mock_prisma)
 
         payload = {