Last name รัตนนุกูลชัย (รัตนนุกูลชัย 
) , across the world, is an extremely rare surname. The family name รัตนนุกูลชัย is habitual in South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| รัตนนุกูลชัย | Thailand |