Surname コスキ (Koski 
, コスキ 
) , throughout the world, is a common last name. The surname コスキ is habitual in Northern Europe, particularly Finland, where it is a common surname, Estonia, where it is quite a rare surname, and Sweden. Measured by absolute frequency, it most frequently occurs in Finland, the United States, and Canada. Very seldom, コスキ is the forename as well as the last name.