diff --git a/libs/langchain/langchain/agents/openai_assistant/base.py b/libs/langchain/langchain/agents/openai_assistant/base.py
index 84d99c8f97..67e361b02e 100644
--- a/libs/langchain/langchain/agents/openai_assistant/base.py
+++ b/libs/langchain/langchain/agents/openai_assistant/base.py
@@ -146,8 +146,8 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
 
     """  # noqa: E501
 
-    client: openai.OpenAI = Field(default_factory=_get_openai_client)
-    """OpenAI client."""
+    client: Any = Field(default_factory=_get_openai_client)
+    """OpenAI or AzureOpenAI client."""
     assistant_id: str
     """OpenAI assistant id."""
     check_every_ms: float = 1_000.0
@@ -163,7 +163,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
         tools: Sequence[Union[BaseTool, dict]],
         model: str,
         *,
-        client: Optional[openai.OpenAI] = None,
+        client: Optional[Union[openai.OpenAI, openai.AzureOpenAI]] = None,
         **kwargs: Any,
     ) -> OpenAIAssistantRunnable:
         """Create an OpenAI Assistant and instantiate the Runnable.
@@ -173,7 +173,8 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
             instructions: Assistant instructions.
             tools: Assistant tools. Can be passed in OpenAI format or as BaseTools.
             model: Assistant model to use.
-            client: OpenAI client. Will create default client if not specified.
+            client: OpenAI or AzureOpenAI client.
+                Will create default OpenAI client if not specified.
 
         Returns:
             OpenAIAssistantRunnable configured to run using the created assistant.
@@ -191,7 +192,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
             tools=openai_tools,
             model=model,
         )
-        return cls(assistant_id=assistant.id, **kwargs)
+        return cls(assistant_id=assistant.id, client=client, **kwargs)
 
     def invoke(
         self, input: dict, config: Optional[RunnableConfig] = None
diff --git a/libs/langchain/tests/unit_tests/agents/test_openai_assistant.py b/libs/langchain/tests/unit_tests/agents/test_openai_assistant.py
new file mode 100644
index 0000000000..aaa4ba48d1
--- /dev/null
+++ b/libs/langchain/tests/unit_tests/agents/test_openai_assistant.py
@@ -0,0 +1,21 @@
+import pytest
+
+from langchain.agents.openai_assistant import OpenAIAssistantRunnable
+
+
+@pytest.mark.requires("openai")
+def test_user_supplied_client() -> None:
+    import openai
+
+    client = openai.AzureOpenAI(
+        azure_endpoint="azure_endpoint",
+        api_key="api_key",
+        api_version="api_version",
+    )
+
+    assistant = OpenAIAssistantRunnable(
+        assistant_id="assistant_id",
+        client=client,
+    )
+
+    assert assistant.client == client