Surname กุลหิรัญ (กุลหิรัญ 
, Kulhirun , Koolhiran ) , around the world, is a very rare last name. The last name กุลหิรัญ is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Very seldom, กุลหิรัญ is the forename as well as the last name.