Cognomen Kupay (Kupay 
, Купай 
) , in all the world, is a rare last name. The cognomen Kupay is habitual in Hungary, where it is a rare surname, Turkey, where it is a very rare surname, and Kyrgyzstan. Measured by absolute frequency, it is commonest in Russia, Turkey, and the United States. Very seldom, Kupay is the forename as well as the last name.