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