Family name Ndai (Ndai 
) , all over the world, is quite a rare surname. The cognomen Ndai is habitual in Sub-Saharan Africa, particularly Kenya, where it is quite a rare surname, the Democratic Republic of the Congo, where it is a rare surname, and Tanzania. Measured by absolute frequency, it is commonest in Kenya, the Democratic Republic of the Congo, and Indonesia. Very seldom, Ndai is the forename as well as the last name.