diff --git a/homeassistant/components/mqtt/__init__.py b/homeassistant/components/mqtt/__init__.py
index 6c70b39c964..2123625bffb 100644
--- a/homeassistant/components/mqtt/__init__.py
+++ b/homeassistant/components/mqtt/__init__.py
@@ -241,6 +241,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             websocket_api.async_register_command(hass, websocket_subscribe)
             websocket_api.async_register_command(hass, websocket_mqtt_info)
             hass.data[DATA_MQTT] = mqtt_data = MqttData(config=mqtt_yaml, client=client)
+            get_mqtt_data.cache_clear()
         client.start(mqtt_data)
 
         # Restore saved subscriptions
diff --git a/homeassistant/components/mqtt/util.py b/homeassistant/components/mqtt/util.py
index 6f8392c5cf1..6f9fb8316bb 100644
--- a/homeassistant/components/mqtt/util.py
+++ b/homeassistant/components/mqtt/util.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+from functools import lru_cache
 import os
 from pathlib import Path
 import tempfile
@@ -216,6 +217,7 @@ def valid_birth_will(config: ConfigType) -> ConfigType:
     return config
 
 
+@lru_cache(maxsize=1)
 def get_mqtt_data(hass: HomeAssistant) -> MqttData:
     """Return typed MqttData from hass.data[DATA_MQTT]."""
     mqtt_data: MqttData = hass.data[DATA_MQTT]