Cognomen Bryun (Bryun 
, Брюн 
) , across the world, is a rare family name. The cognomen Bryun is habitual in Eastern Europe, particularly Bulgaria, where it is quite a rare surname, Russia, where it is a rare surname, and Ukraine, where it is an extremely rare surname. Measured by absolute frequency, it is commonest in Russia, Bulgaria, and the United States. Much less frequently, Bryun is the forename as well as the last name.