diff --git a/homeassistant/components/webostv/media_player.py b/homeassistant/components/webostv/media_player.py
index 6aef47515dbbfb..099b5a73784924 100644
--- a/homeassistant/components/webostv/media_player.py
+++ b/homeassistant/components/webostv/media_player.py
@@ -239,7 +239,8 @@ def _update_states(self) -> None:
 
         self._attr_assumed_state = True
         if (
-            self._client.media_state is not None
+            self._client.is_on
+            and self._client.media_state is not None
             and self._client.media_state.get("foregroundAppInfo") is not None
         ):
             self._attr_assumed_state = False
diff --git a/tests/components/webostv/test_media_player.py b/tests/components/webostv/test_media_player.py
index 6c4aeb5e9840fb..f0d17057b33fc2 100644
--- a/tests/components/webostv/test_media_player.py
+++ b/tests/components/webostv/test_media_player.py
@@ -832,3 +832,7 @@ async def test_update_media_state(hass: HomeAssistant, client, monkeypatch) -> N
     monkeypatch.setattr(client, "media_state", data)
     await client.mock_state_update()
     assert hass.states.get(ENTITY_ID).state == MediaPlayerState.IDLE
+
+    monkeypatch.setattr(client, "is_on", False)
+    await client.mock_state_update()
+    assert hass.states.get(ENTITY_ID).state == STATE_OFF