Surname Данай (Danai 
, Danay 
, Danaj 
) , in the world, is a common last name. The cognomen Данай is habitual in Albania, where it is quite a common surname, Greece, and Nepal, where it is quite a rare surname. Not in comparison with a country's population, it is commonest in Greece, India, and Albania. More prevalently, Данай is the forename as well as the last name.