Cognomen Mubai (慕白 
, Mubai 
) , across the world, is a rare last name. The cognomen Mubai is habitual in Mozambique, where it is quite a rare surname, South Africa, where it is a very rare surname, and China, where it is an extremely rare surname. In absolute terms, it is the most numerous in Mozambique, China, and India. Also, Mubai is the forename as well as the last name.