Cognomen Vayder (Vayder 
, Вайдэр 
, Вайдер 
) , around the globe, is a rare family name. The surname Vayder is habitual in Belarus, where it is a rare surname, Bulgaria, and Kazakhstan, where it is a very rare surname. Measured by absolute frequency, it most frequently occurs in Russia, Belarus, and the United States. Much less frequently, Vayder is the forename as well as the last name.