Cognomen Rungnithichakul (Rungnithichakul 
) , in all the world, is an extremely rare family name. The cognomen Rungnithichakul is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Rungnithichakul | Thailand |
Napuk, and Thayaporathorn