Last name เพชรพิชัย (เพชรพิชัย 
, Petchpichai , Phetpichai 
) , all around the world, is a rare surname. The surname เพชรพิชัย is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname. Much less frequently, เพชรพิชัย is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Petchpichai, เพชรพิชัย, Pechphichai | Thailand |
| Phetpichai | Thailand, United States |