Cognomen Karnthong (Karnthong 
) , in all the world, is a very rare surname. The surname Karnthong is characteristic of Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname. Much less frequently, Karnthong is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Karnthong | Thailand, United States |