Last name เพศ (Bayan 
, Gend 
, Phet 
) , across the world, is a common family name. The cognomen เพศ is characteristic of Israel, where it is quite a common surname, Lebanon, and Laos, where it is quite a rare surname. Not in comparison with a country's population, it is the most numerous in India, Philippines, and Indonesia. Also, เพศ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Bayan | Philippines, Iraq, India, Syria, Saudi Arabia |
| Gend | Philippines, India, Indonesia, Malaysia, Algeria |
| Phet | Philippines, Thailand, Laos, India, Indonesia |
| เพศ | Thailand |