Last name រិទ្ថ (រិទ្ថ 
) , around the world, is an extremely rare family name. The family name រិទ្ថ is characteristic of South-eastern Asia, particularly Cambodia, where it is a very rare surname. Also, រិទ្ថ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| រិទ្ថ | Cambodia |