Cognomen ทรสิทธิ์ (ทรสิทธิ์ 
) , across the world, is a very rare last name. The cognomen ทรสิทธิ์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Much less frequently, ทรสิทธิ์ is the forename as well as the last name.