Family name Vaian (Vaian 
, Ваян 
) , in all the world, is a very rare cognomen. The family name Vaian is habitual in Russia, where it is a very rare surname, Ukraine, where it is an extremely rare surname, and Brazil. Measured by absolute frequency, it is commonest in Russia, Brazil, and India. Much less frequently, Vaian is the forename as well as the last name.