Surname สิทธิบุญ (สิทธิบุญ 
, Sittibun , Sitthibun ) , throughout the world, is a rare last name. The cognomen สิทธิบุญ is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, สิทธิบุญ is the forename as well as the last name.