Cognomen กุลวัฒนศักดิ์ (กุลวัฒนศักดิ์ 
, Kulwatanasak 
) , around the globe, is a very rare surname. The surname กุลวัฒนศักดิ์ is habitual in Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| กุลวัฒนศักดิ์ | Thailand |
| Kulwatanasak | United States, Thailand |