Cognomen Phommaxay (Phommaxay 
) , in all the world, is quite a rare family name. The family name Phommaxay is characteristic of Laos, where it is quite a common surname, Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phommaxay | Laos, United States, Thailand |