diff --git a/chatstream/__init__.py b/chatstream/__init__.py
index d6b6806..d19f97c 100644
--- a/chatstream/__init__.py
+++ b/chatstream/__init__.py
@@ -111,6 +111,10 @@ class chat_server:
     ----------
     model
         OpenAI model to use. Can be a string or a function that returns a string.
+    azure_deployment_id
+        Azure deployment ID to use (optional). Azure supports the OpenAI API, but with
+        some slight changes. If you are using Azure, you must set this to the your
+        deployment ID. Can be a string or a function that return a string.
     api_key
         OpenAI API key to use (optional). Can be a string or a function that returns a
         string, or `None`. If `None`, then it will use the `OPENAI_API_KEY` environment
@@ -124,7 +128,7 @@ class chat_server:
     temperature
         Temperature to use. Can be a float or a function that returns a float.
     text_input_placeholder
-        Placeholder teext to use for the text input. Can be a string or a function that
+        Placeholder text to use for the text input. Can be a string or a function that
         returns a string, or `None` for no placeholder.
     throttle
         Throttle interval to use for incoming streaming messages. Can be a float or a
@@ -164,6 +168,7 @@ def __init__(
         session: Session,
         *,
         model: OpenAiModel | Callable[[], OpenAiModel] = DEFAULT_MODEL,
+        azure_deployment_id: str | Callable[[], str] | None = None,
         api_key: str | Callable[[], str] | None = None,
         url: str | Callable[[], str] | None = None,
         system_prompt: str | Callable[[], str] = DEFAULT_SYSTEM_PROMPT,
@@ -189,6 +194,12 @@ def __init__(
             Callable[[], OpenAiModel],
             wrap_function_nonreactive(model),
         )
+
+        if azure_deployment_id is None:
+            self.azure_deployment_id = None
+        else:
+            self.azure_deployment_id = wrap_function_nonreactive(azure_deployment_id)
+
         if api_key is None:
             self.api_key = get_env_var_api_key
         else:
@@ -338,13 +349,19 @@ async def perform_query():
             if self.url() is not None:
                 extra_kwargs["url"] = self.url()
 
+            if self.azure_deployment_id is not None:
+                # Azure-OpenAI uses deployment_id instead of model.
+                extra_kwargs["deployment_id"] = self.azure_deployment_id()
+            else:
+                # OpenAI just uses model.
+                extra_kwargs["model"] = self.model()
+
             # Launch a Task that updates the chat string asynchronously. We run this in
             # a separate task so that the data can come in without need to await it in
             # this Task (which would block other computation to happen, like running
             # reactive stuff).
             messages: StreamResult[ChatCompletionStreaming] = stream_to_reactive(
                 openai.ChatCompletion.acreate(  # pyright: ignore[reportUnknownMemberType, reportGeneralTypeIssues]
-                    model=self.model(),
                     api_key=self.api_key(),
                     messages=outgoing_messages_normalized,
                     stream=True,
diff --git a/chatstream/openai_types.py b/chatstream/openai_types.py
index f790cf8..bca06fc 100644
--- a/chatstream/openai_types.py
+++ b/chatstream/openai_types.py
@@ -15,6 +15,7 @@
     "gpt-4-32k-0314",
 ]
 
+
 openai_model_context_limits: dict[OpenAiModel, int] = {
     "gpt-3.5-turbo": 4096,
     "gpt-3.5-turbo-16k": 16384,