Across the world, Kelsen (Kelsen 
, קלזן 
) is a rare predominantly male, but scarcely feminine forename. The given name Kelsen is habitual in Brazil, where it is a very rare predominantly masculine, but very seldom girly name, Indonesia, where it is a very rare masculine name, and Mexico, where it is an extremely rare male name. In absolute terms, it is commonest in Brazil, Indonesia, and the United States. Also, Kelsen is the last name as well as the forename.