Last name โรจน์รัตน์ (โรจน์รัตน์ 
, Rojrat ) , in the entire world, is a very rare cognomen. The cognomen โรจน์รัตน์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, โรจน์รัตน์ is the forename as well as the last name.