Surname ศิทธิศักดิ์ (ศิทธิศักดิ์ 
) , in all the world, is an extremely rare last name. The cognomen ศิทธิศักดิ์ is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname. More prevalently, ศิทธิศักดิ์ is the forename as well as the last name.