diff --git a/litellm/llms/vertex_ai/gemini/transformation.py b/litellm/llms/vertex_ai/gemini/transformation.py
index 327b269d1d..c59e3bb24e 100644
--- a/litellm/llms/vertex_ai/gemini/transformation.py
+++ b/litellm/llms/vertex_ai/gemini/transformation.py
@@ -28,6 +28,7 @@ from litellm.types.files import (
     get_file_type_from_extension,
     is_gemini_1_5_accepted_file_type,
 )
+from litellm.types.utils import LlmProviders
 from litellm.types.llms.openai import (
     AllMessageValues,
     ChatCompletionAssistantMessage,
@@ -492,7 +493,8 @@ def _transform_request_body(
             data["generationConfig"] = generation_config
         if cached_content is not None:
             data["cachedContent"] = cached_content
-        if labels is not None:
+        # Only add labels for Vertex AI endpoints (not Google GenAI/AI Studio) and only if non-empty
+        if labels and custom_llm_provider != LlmProviders.GEMINI:
             data["labels"] = labels
     except Exception as e:
         raise e
@@ -647,3 +649,5 @@ def _transform_system_message(
         return SystemInstructions(parts=system_content_blocks), messages
 
     return None, messages
+
+
diff --git a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
index d6d3325857..4da2976e1f 100644
--- a/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
+++ b/tests/test_litellm/llms/vertex_ai/gemini/test_vertex_ai_gemini_transformation.py
@@ -1,4 +1,7 @@
-from litellm.llms.vertex_ai.gemini.transformation import check_if_part_exists_in_parts
+from litellm.llms.vertex_ai.gemini.transformation import (
+    check_if_part_exists_in_parts,
+    _transform_request_body,
+)
 
 
 def test_check_if_part_exists_in_parts():
@@ -73,3 +76,82 @@ def test_check_if_part_exists_in_parts_camel_case_snake_case():
     }
 
     assert check_if_part_exists_in_parts(parts_mixed, part_mixed_casing)
+
+
+# Tests for issue #14556: Labels field provider-aware filtering
+def test_google_genai_excludes_labels():
+    """Test that Google GenAI/AI Studio endpoints exclude labels when custom_llm_provider='gemini'"""
+    messages = [{"role": "user", "content": "test"}]
+    optional_params = {"labels": {"project": "test", "team": "ai"}}
+    litellm_params = {}
+
+    result = _transform_request_body(
+        messages=messages,
+        model="gemini-2.5-pro",
+        optional_params=optional_params,
+        custom_llm_provider="gemini",
+        litellm_params=litellm_params,
+        cached_content=None,
+    )
+
+    # Google GenAI/AI Studio should NOT include labels
+    assert "labels" not in result
+    assert "contents" in result
+
+
+def test_vertex_ai_includes_labels():
+    """Test that Vertex AI endpoints include labels when custom_llm_provider='vertex_ai'"""
+    messages = [{"role": "user", "content": "test"}]
+    optional_params = {"labels": {"project": "test", "team": "ai"}}
+    litellm_params = {}
+
+    result = _transform_request_body(
+        messages=messages,
+        model="gemini-2.5-pro",
+        optional_params=optional_params,
+        custom_llm_provider="vertex_ai",
+        litellm_params=litellm_params,
+        cached_content=None,
+    )
+
+    # Vertex AI SHOULD include labels
+    assert "labels" in result
+    assert result["labels"] == {"project": "test", "team": "ai"}
+
+
+
+def test_metadata_to_labels_vertex_only():
+    """Test that metadata->labels conversion only happens for Vertex AI"""
+    messages = [{"role": "user", "content": "test"}]
+    optional_params = {}
+    litellm_params = {
+        "metadata": {
+            "requester_metadata": {
+                "user": "john_doe",
+                "project": "test-project"
+            }
+        }
+    }
+
+    # Google GenAI/AI Studio should not include labels from metadata
+    result = _transform_request_body(
+        messages=messages,
+        model="gemini-2.5-pro",
+        optional_params=optional_params.copy(),
+        custom_llm_provider="gemini",
+        litellm_params=litellm_params.copy(),
+        cached_content=None,
+    )
+    assert "labels" not in result
+
+    # Vertex AI should include labels from metadata
+    result = _transform_request_body(
+        messages=messages,
+        model="gemini-2.5-pro",
+        optional_params=optional_params.copy(),
+        custom_llm_provider="vertex_ai",
+        litellm_params=litellm_params.copy(),
+        cached_content=None,
+    )
+    assert "labels" in result
+    assert result["labels"] == {"user": "john_doe", "project": "test-project"}