Surname สมิทธิพงศ์ (สมิทธิพงศ์ 
) , around the world, is a very rare last name. The surname สมิทธิพงศ์ is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Also, สมิทธิพงศ์ is the forename as well as the last name.