diff --git a/python/packages/main/agent_framework/_agents.py b/python/packages/main/agent_framework/_agents.py
index 66f1c8f2df..7e3843a013 100644
--- a/python/packages/main/agent_framework/_agents.py
+++ b/python/packages/main/agent_framework/_agents.py
@@ -491,6 +491,7 @@ class ChatClientAgent(AgentBase):
         """
         input_messages = self._normalize_messages(messages)
         thread, thread_messages = await self._prepare_thread_and_messages(thread=thread, input_messages=input_messages)
+        agent_name = self._get_agent_name()
 
         response = await self.chat_client.get_response(
             messages=thread_messages,
@@ -519,6 +520,11 @@ class ChatClientAgent(AgentBase):
 
         self._update_thread_with_type_and_conversation_id(thread, response.conversation_id)
 
+        # Ensure that the author name is set for each message in the response.
+        for message in response.messages:
+            if message.author_name is None:
+                message.author_name = agent_name
+
         # Only notify the thread of new messages if the chatResponse was successful
         # to avoid inconsistent messages state in the thread.
         await self._notify_thread_of_new_messages(thread, input_messages)
@@ -595,6 +601,7 @@ class ChatClientAgent(AgentBase):
         """
         input_messages = self._normalize_messages(messages)
         thread, thread_messages = await self._prepare_thread_and_messages(thread=thread, input_messages=input_messages)
+        agent_name = self._get_agent_name()
         response_updates: list[ChatResponseUpdate] = []
 
         async for update in self.chat_client.get_streaming_response(
@@ -622,6 +629,10 @@ class ChatClientAgent(AgentBase):
             **kwargs,
         ):
             response_updates.append(update)
+
+            if update.author_name is None:
+                update.author_name = agent_name
+
             yield AgentRunResponseUpdate(
                 contents=update.contents,
                 role=update.role,
@@ -720,3 +731,6 @@ class ChatClientAgent(AgentBase):
             return [messages]
 
         return [ChatMessage(role=ChatRole.USER, text=msg) if isinstance(msg, str) else msg for msg in messages]
+
+    def _get_agent_name(self) -> str:
+        return self.name or "UnnamedAgent"
diff --git a/python/packages/main/tests/main/test_agents.py b/python/packages/main/tests/main/test_agents.py
index bd514c0a60..4bb3f874c8 100644
--- a/python/packages/main/tests/main/test_agents.py
+++ b/python/packages/main/tests/main/test_agents.py
@@ -43,6 +43,11 @@ class MockAgent(AIAgent):
         """Returns the name of the agent."""
         return "Name"
 
+    @property
+    def display_name(self) -> str:
+        """Returns the name of the agent."""
+        return "Display Name"
+
     @property
     def description(self) -> str | None:
         return "Description"
@@ -243,7 +248,7 @@ async def test_chat_client_agent_prepare_thread_and_messages(chat_client: ChatCl
     message = ChatMessage(role=ChatRole.USER, text="Hello")
     thread = ChatClientAgentThread(messages=[message])
 
-    result_thread = agent._validate_or_create_thread_type(
+    result_thread = agent._validate_or_create_thread_type(  # type: ignore[reportPrivateUsage]
         thread, lambda: ChatClientAgentThread(), expected_type=ChatClientAgentThread
     )  # type: ignore[reportPrivateUsage]
 
@@ -264,7 +269,7 @@ async def test_chat_client_agent_validate_or_create_thread(chat_client: ChatClie
     agent = ChatClientAgent(chat_client=chat_client)
     thread = None
 
-    result_thread = agent._validate_or_create_thread_type(
+    result_thread = agent._validate_or_create_thread_type(  # type: ignore[reportPrivateUsage]
         thread, lambda: ChatClientAgentThread(), expected_type=ChatClientAgentThread
     )  # type: ignore[reportPrivateUsage]
 
@@ -313,3 +318,36 @@ async def test_chat_client_agent_update_thread_conversation_id_missing(chat_clie
 
     with raises(AgentExecutionException, match="Service did not return a valid conversation id"):
         agent._update_thread_with_type_and_conversation_id(thread, None)  # type: ignore[reportPrivateUsage]
+
+
+async def test_chat_client_agent_default_author_name(chat_client: ChatClient) -> None:
+    # Name is not specified here, so default name should be used
+    agent = ChatClientAgent(chat_client=chat_client)
+
+    result = await agent.run("Hello")
+    assert result.text == "test response"
+    assert result.messages[0].author_name == "UnnamedAgent"
+
+
+async def test_chat_client_agent_author_name_as_agent_name(chat_client: ChatClient) -> None:
+    # Name is specified here, so it should be used as author name
+    agent = ChatClientAgent(chat_client=chat_client, name="TestAgent")
+
+    result = await agent.run("Hello")
+    assert result.text == "test response"
+    assert result.messages[0].author_name == "TestAgent"
+
+
+async def test_chat_client_agent_author_name_is_used_from_response() -> None:
+    chat_client = MockChatClient(
+        mock_response=ChatResponse(
+            messages=[
+                ChatMessage(role=ChatRole.ASSISTANT, contents=[TextContent("test response")], author_name="TestAuthor")
+            ]
+        )
+    )
+    agent = ChatClientAgent(chat_client=chat_client)
+
+    result = await agent.run("Hello")
+    assert result.text == "test response"
+    assert result.messages[0].author_name == "TestAuthor"