Cognomen ฤทธิกุลทอง (ฤทธิกุลทอง 
) , in the entire world, is an extremely rare family name. The cognomen ฤทธิกุลทอง is characteristic of South-eastern Asia, particularly Thailand, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| ฤทธิกุลทอง | Thailand |