Family name Phonarjthan (Phonarjthan 
) , throughout the world, is an extremely rare surname. The cognomen Phonarjthan is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Phonarjthan | Thailand |
| patompob phonarjthan Thai cyclist, TH (b. 1997) |
|