Surname Kolchak (Kolchak 
, Колчак , קולצ'ק 
) , across the world, is a rare cognomen. The cognomen Kolchak is habitual in Ukraine, where it is quite a rare surname, Russia, where it is a rare surname, and Kazakhstan, where it is a very rare surname. Not in comparison with a country's population, it most frequently occurs in Ukraine, Russia, and France.