Cognomen พรหมไทย (พรหมไทย 
, Promthai , Phomthai 
) , globally, is a rare family name. The family name พรหมไทย is habitual in South-eastern Asia, particularly Laos, where it is a rare surname, and Thailand.
| VARIANT | COUNTRY |
|---|---|
| Promthai, พรหมไทย, Phromthai | Thailand |
| Phomthai | Laos, Thailand |