diff --git a/esphome/components/datetime/__init__.py b/esphome/components/datetime/__init__.py
index b255a27303..a22c60aae9 100644
--- a/esphome/components/datetime/__init__.py
+++ b/esphome/components/datetime/__init__.py
@@ -106,8 +106,8 @@ def datetime_schema(class_: MockObjClass) -> cv.Schema:
 async def setup_datetime_core_(var, config):
     await setup_entity(var, config)
 
-    if CONF_MQTT_ID in config:
-        mqtt_ = cg.new_Pvariable(config[CONF_MQTT_ID], var)
+    if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:
+        mqtt_ = cg.new_Pvariable(mqtt_id, var)
         await mqtt.register_mqtt_component(mqtt_, config)
     for conf in config.get(CONF_ON_VALUE, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)