Cognomen Khamkhen (Khamkhen 
, คำเพ็ญ) , across the world, is a very rare surname. The last name Khamkhen is habitual in Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname. Very seldom, Khamkhen is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Khamkhen | United States, India, Thailand |