Cognomen Kosaty (Kosaty 
, Косатый 
) , all over the world, is a rare last name. The cognomen Kosaty is habitual in Belarus, where it is a rare surname, Kazakhstan, and Poland, where it is a very rare surname. In absolute terms, it is commonest in Eastern Europe, particularly Russia, Belarus, and Poland. Much less frequently, Kosaty is the forename as well as the last name.