Cognomen Phiothongngam (Phiothongngam 
) , throughout the world, is a very rare last name. The family name Phiothongngam is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phiothongngam | Thailand |
Amares, Suphakij, and Phanthanakan