Meaning A boy's name of Welsh origin, it means "Variant of Cai: Joy." Origin of Caio Welsh Popular Middle Names Alessandro, King, Raffaele Pronunciation 🔊 Listen Caio Similar Names Caswallon Bearach Gawain Gwydyon Aadidev Erbin Fercos Fychan Gwallawg Kywrkh Year by Year Popularity of Caio