Last name เพ็ญจันทร (เพ็ญจันทร 
) , across the world, is an extremely rare cognomen. The cognomen เพ็ญจันทร is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname. More prevalently, เพ็ญจันทร is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| เพ็ญจันทร | Thailand |