Surname สุนทรหิรัญ (สุนทรหิรัญ 
, Sunthonhiran) , in the world, is a very rare family name. The family name สุนทรหิรัญ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, สุนทรหิรัญ is the forename as well as the last name.