Cognomen Niwetmethakun (Niwetmethakun 
) , across the world, is a very rare last name. The surname Niwetmethakun is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Niwetmethakun | Thailand |
Wachira, and Phathraporn