Family name Phouthonesy (Phouthonesy 
) , around the world, is a rare last name. The cognomen Phouthonesy is habitual in Laos, where it is quite a rare surname, Canada, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phouthonesy | Laos, United States, Canada |