Family name Phongthirath (Phongthirath 
) , globally, is an extremely rare last name. The surname Phongthirath is characteristic of Northern America, particularly the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phongthirath | United States |
Sam, Chon, Vannaly, Rungnakho, and Rungnakhone