Cognomen สิทธิบูรณ์ (สิทธิบูรณ์ 
, Sittiboon ) , in the entire world, is a rare family name. The family name สิทธิบูรณ์ is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, สิทธิบูรณ์ is the forename as well as the last name.