Cognomen Romthum (Romthum 
) , around the globe, is a very rare last name. The family name Romthum is habitual in Thailand, where it is a very rare surname, and Brazil, where it is an extremely rare surname. Very seldom, Romthum is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Romthum | Brazil, Thailand |