diff --git a/homeassistant/components/conversation/agent.py b/homeassistant/components/conversation/agent.py
index 0056f35def6..18a2f4edf56 100644
--- a/homeassistant/components/conversation/agent.py
+++ b/homeassistant/components/conversation/agent.py
@@ -49,6 +49,11 @@ class AbstractConversationAgent(ABC):
         """Return the attribution."""
         return None
 
+    @property
+    @abstractmethod
+    def supported_languages(self) -> list[str]:
+        """Return a list of supported languages."""
+
     @abstractmethod
     async def async_process(self, user_input: ConversationInput) -> ConversationResult:
         """Process a sentence."""
diff --git a/homeassistant/components/conversation/default_agent.py b/homeassistant/components/conversation/default_agent.py
index 02d90d1c8dd..b3a66d80307 100644
--- a/homeassistant/components/conversation/default_agent.py
+++ b/homeassistant/components/conversation/default_agent.py
@@ -13,7 +13,7 @@ from typing import IO, Any
 from hassil.intents import Intents, ResponseType, SlotList, TextSlotList
 from hassil.recognize import RecognizeResult, recognize_all
 from hassil.util import merge_dict
-from home_assistant_intents import get_intents
+from home_assistant_intents import get_domains_and_languages, get_intents
 import yaml
 
 from homeassistant import core, setup
@@ -86,6 +86,11 @@ class DefaultAgent(AbstractConversationAgent):
         self._config_intents: dict[str, Any] = {}
         self._slot_lists: dict[str, SlotList] | None = None
 
+    @property
+    def supported_languages(self) -> list[str]:
+        """Return a list of supported languages."""
+        return get_domains_and_languages()["homeassistant"]
+
     async def async_initialize(self, config_intents):
         """Initialize the default agent."""
         if "intent" not in self.hass.config.components:
diff --git a/homeassistant/components/google_assistant_sdk/__init__.py b/homeassistant/components/google_assistant_sdk/__init__.py
index 93699321eda..7a9ca70bf14 100644
--- a/homeassistant/components/google_assistant_sdk/__init__.py
+++ b/homeassistant/components/google_assistant_sdk/__init__.py
@@ -150,6 +150,14 @@ class GoogleAssistantConversationAgent(conversation.AbstractConversationAgent):
             "url": "https://www.home-assistant.io/integrations/google_assistant_sdk/",
         }
 
+    @property
+    def supported_languages(self) -> list[str]:
+        """Return a list of supported languages."""
+        language_code = self.entry.options.get(
+            CONF_LANGUAGE_CODE, default_language_code(self.hass)
+        )
+        return [language_code]
+
     async def async_process(
         self, user_input: conversation.ConversationInput
     ) -> conversation.ConversationResult:
diff --git a/homeassistant/components/openai_conversation/__init__.py b/homeassistant/components/openai_conversation/__init__.py
index 6f76142106a..d6eeb85e06a 100644
--- a/homeassistant/components/openai_conversation/__init__.py
+++ b/homeassistant/components/openai_conversation/__init__.py
@@ -9,7 +9,7 @@ from openai import error
 
 from homeassistant.components import conversation
 from homeassistant.config_entries import ConfigEntry
-from homeassistant.const import CONF_API_KEY
+from homeassistant.const import CONF_API_KEY, MATCH_ALL
 from homeassistant.core import HomeAssistant
 from homeassistant.exceptions import ConfigEntryNotReady, TemplateError
 from homeassistant.helpers import intent, template
@@ -70,6 +70,11 @@ class OpenAIAgent(conversation.AbstractConversationAgent):
         """Return the attribution."""
         return {"name": "Powered by OpenAI", "url": "https://www.openai.com"}
 
+    @property
+    def supported_languages(self) -> list[str]:
+        """Return a list of supported languages."""
+        return [MATCH_ALL]
+
     async def async_process(
         self, user_input: conversation.ConversationInput
     ) -> conversation.ConversationResult:
diff --git a/tests/components/conversation/__init__.py b/tests/components/conversation/__init__.py
index 4812411fe23..db233be04cf 100644
--- a/tests/components/conversation/__init__.py
+++ b/tests/components/conversation/__init__.py
@@ -18,6 +18,11 @@ class MockAgent(conversation.AbstractConversationAgent):
         self.calls = []
         self.response = "Test response"
 
+    @property
+    def supported_languages(self) -> list[str]:
+        """Return a list of supported languages."""
+        return ["smurfish"]
+
     async def async_process(
         self, user_input: conversation.ConversationInput
     ) -> conversation.ConversationResult:
diff --git a/tests/components/conversation/test_default_agent.py b/tests/components/conversation/test_default_agent.py
index f375d3ca1e3..810e2905034 100644
--- a/tests/components/conversation/test_default_agent.py
+++ b/tests/components/conversation/test_default_agent.py
@@ -1,4 +1,5 @@
 """Test for the default agent."""
+from unittest.mock import patch
 
 import pytest
 
@@ -121,3 +122,18 @@ async def test_exposed_areas(
     # This should be an intent match failure because the area isn't in the slot list
     assert result.response.response_type == intent.IntentResponseType.ERROR
     assert result.response.error_code == intent.IntentResponseErrorCode.NO_INTENT_MATCH
+
+
+async def test_conversation_agent(
+    hass: HomeAssistant,
+    init_components,
+) -> None:
+    """Test DefaultAgent."""
+    agent = await conversation._get_agent_manager(hass).async_get_agent(
+        conversation.HOME_ASSISTANT_AGENT
+    )
+    with patch(
+        "homeassistant.components.conversation.default_agent.get_domains_and_languages",
+        return_value={"homeassistant": ["dwarvish", "elvish", "entish"]},
+    ):
+        assert agent.supported_languages == ["dwarvish", "elvish", "entish"]
diff --git a/tests/components/google_assistant_sdk/test_init.py b/tests/components/google_assistant_sdk/test_init.py
index 293b42fa57b..837f98ad4b9 100644
--- a/tests/components/google_assistant_sdk/test_init.py
+++ b/tests/components/google_assistant_sdk/test_init.py
@@ -7,6 +7,7 @@ from unittest.mock import call, patch
 import aiohttp
 import pytest
 
+from homeassistant.components import conversation
 from homeassistant.components.google_assistant_sdk import DOMAIN
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.core import HomeAssistant
@@ -334,6 +335,9 @@ async def test_conversation_agent(
     )
     await hass.async_block_till_done()
 
+    agent = await conversation._get_agent_manager(hass).async_get_agent(entry.entry_id)
+    assert agent.supported_languages == ["en-US"]
+
     text1 = "tell me a joke"
     text2 = "tell me another one"
     with patch(
diff --git a/tests/components/openai_conversation/test_init.py b/tests/components/openai_conversation/test_init.py
index 144d77beab5..62136ecfffd 100644
--- a/tests/components/openai_conversation/test_init.py
+++ b/tests/components/openai_conversation/test_init.py
@@ -137,3 +137,15 @@ async def test_template_error(
 
     assert result.response.response_type == intent.IntentResponseType.ERROR, result
     assert result.response.error_code == "unknown", result
+
+
+async def test_conversation_agent(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_init_component,
+) -> None:
+    """Test OpenAIAgent."""
+    agent = await conversation._get_agent_manager(hass).async_get_agent(
+        mock_config_entry.entry_id
+    )
+    assert agent.supported_languages == ["*"]