Family name ฤทธิรัตนกุล (ฤทธิรัตนกุล 
) , around the world, is a very rare last name. The last name ฤทธิรัตนกุล is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| ฤทธิรัตนกุล | Thailand |
ปกรณ์ศักดิ์, and ศิริสุดา