Cognomen รัตนเกษม (Ratanakasem 
, รัตนเกษม , Rattanakaes) , in the entire world, is a very rare family name. The cognomen รัตนเกษม is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Very seldom, รัตนเกษม is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ratanakasem, รัตนเกษม | Thailand |
Ratanakased, Rattanakased, Rattanakasem, Rattanakasempham, and Rattanakasemphe