Cognomen มหาวันแจ่ม (มหาวันแจ่ม, Mahawanchaem 
) , throughout the world, is an extremely rare last name. The surname มหาวันแจ่ม is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Mahawanchaem | Thailand |