Cognomen กุลสิทธิ์ (กุลสิทธิ์ 
, Kulasit 
, Kunsit 
) , around the globe, is a rare family name. The last name กุลสิทธิ์ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname, and Malaysia, where it is a very rare surname. Much less frequently, กุลสิทธิ์ is the forename as well as the last name.