diff --git a/homeassistant/components/conversation/agent.py b/homeassistant/components/conversation/agent.py
index 18a2f4edf56..162338a6ff0 100644
--- a/homeassistant/components/conversation/agent.py
+++ b/homeassistant/components/conversation/agent.py
@@ -3,7 +3,7 @@ from __future__ import annotations
 
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
-from typing import Any, TypedDict
+from typing import Any, Literal, TypedDict
 
 from homeassistant.core import Context
 from homeassistant.helpers import intent
@@ -51,7 +51,7 @@ class AbstractConversationAgent(ABC):
 
     @property
     @abstractmethod
-    def supported_languages(self) -> list[str]:
+    def supported_languages(self) -> list[str] | Literal["*"]:
         """Return a list of supported languages."""
 
     @abstractmethod
diff --git a/homeassistant/components/openai_conversation/__init__.py b/homeassistant/components/openai_conversation/__init__.py
index d6eeb85e06a..c1b569ce9e1 100644
--- a/homeassistant/components/openai_conversation/__init__.py
+++ b/homeassistant/components/openai_conversation/__init__.py
@@ -3,6 +3,7 @@ from __future__ import annotations
 
 from functools import partial
 import logging
+from typing import Literal
 
 import openai
 from openai import error
@@ -71,9 +72,9 @@ class OpenAIAgent(conversation.AbstractConversationAgent):
         return {"name": "Powered by OpenAI", "url": "https://www.openai.com"}
 
     @property
-    def supported_languages(self) -> list[str]:
+    def supported_languages(self) -> list[str] | Literal["*"]:
         """Return a list of supported languages."""
-        return [MATCH_ALL]
+        return MATCH_ALL
 
     async def async_process(
         self, user_input: conversation.ConversationInput
diff --git a/tests/components/openai_conversation/test_init.py b/tests/components/openai_conversation/test_init.py
index 62136ecfffd..4016ac03c97 100644
--- a/tests/components/openai_conversation/test_init.py
+++ b/tests/components/openai_conversation/test_init.py
@@ -148,4 +148,4 @@ async def test_conversation_agent(
     agent = await conversation._get_agent_manager(hass).async_get_agent(
         mock_config_entry.entry_id
     )
-    assert agent.supported_languages == ["*"]
+    assert agent.supported_languages == "*"