A snorkel mouthpiece assembly, including a main body, a mouthpiece, a connecting component and an accessory, is provided. The mouthpiece is connected to the main body. The connecting component includes a connecting portion and a fixing portion opposite to the connecting portion. The connecting portion is detachably connected to the main body, and the accessory is connected to the fixing portion. In this way, the snorkel mouthpiece assembly could be equipped with a variety of accessories during water or diving activities.