Surname มหาสิทธิ์ (Mahasit 
, มหาสิทธิ์ ) , around the world, is a rare cognomen. The last name มหาสิทธิ์ is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Very seldom, มหาสิทธิ์ is the forename as well as the last name.