Cognomen Madatjan (Мадатян 
, Madatjan 
) , around the world, is a rare last name. The cognomen Madatjan is characteristic of Lithuania, where it is a rare surname, Russia, and Kazakhstan, where it is a very rare surname. Measured by absolute frequency, it is commonest in Russia, Ukraine, and Lithuania. More prevalently, Madatjan is the forename as well as the last name.