diff --git a/langextract/factory.py b/langextract/factory.py
index 21bee178..b29dd042 100644
--- a/langextract/factory.py
+++ b/langextract/factory.py
@@ -68,6 +68,7 @@ def _kwargs_with_environment_defaults(
     env_vars_by_provider = {
         "gemini": ("GEMINI_API_KEY", "LANGEXTRACT_API_KEY"),
         "gpt": ("OPENAI_API_KEY", "LANGEXTRACT_API_KEY"),
+        "o1": ("OPENAI_API_KEY", "LANGEXTRACT_API_KEY"),
     }
 
     for provider_prefix, env_vars in env_vars_by_provider.items():
diff --git a/tests/factory_test.py b/tests/factory_test.py
index db365aaa..9fcac21b 100644
--- a/tests/factory_test.py
+++ b/tests/factory_test.py
@@ -119,6 +119,14 @@ def test_uses_openai_api_key_from_environment(self):
     model = factory.create_model(config)
     self.assertEqual(model.api_key, "env-openai-key")
 
+  @mock.patch.dict(os.environ, {"OPENAI_API_KEY": "env-openai-key"})
+  def test_uses_openai_api_key_for_o1_models(self):
+    """Factory should use OPENAI_API_KEY from env for 'o1-*' OpenAI models."""
+    config = factory.ModelConfig(model_id="o1-mini")
+
+    model = factory.create_model(config)
+    self.assertEqual(model.api_key, "env-openai-key")
+
   @mock.patch.dict(
       os.environ, {"LANGEXTRACT_API_KEY": "env-langextract-key"}, clear=True
   )