Family name ถนอมฤทธิ์ (ถนอมฤทธิ์ 
) , throughout the world, is a very rare surname. The surname ถนอมฤทธิ์ is habitual in South-eastern Asia, particularly Thailand, where it is a very rare surname. Likewise, ถนอมฤทธิ์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| ถนอมฤทธิ์ | Thailand |