Last name สิทธิสัตย์ (สิทธิสัตย์ 
) , all over the world, is a very rare family name. The surname สิทธิสัตย์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, สิทธิสัตย์ is the forename as well as the last name.