Surname Ардай (Ardai 
, Ардай 
) , around the world, is a rare family name. The family name Ардай is habitual in Hungary, where it is quite a rare surname, Romania, where it is a rare surname, and Israel, where it is a very rare surname. Measured by absolute frequency, it is commonest in Hungary, Indonesia, and Romania. Much less frequently, Ардай is the forename as well as the last name.