Cognomen Katsin (Katsin 
, Кацин 
, Катцин ) , throughout the world, is a rare surname. The surname Katsin is habitual in Russia, where it is a rare surname, Ukraine, where it is a very rare surname, and Kazakhstan. In absolute terms, it is the most numerous in Russia, Turkey, and Ukraine. Much less frequently, Katsin is the forename as well as the last name.