Family name ทอนใจ (Regret 
, ทอนใจ 
) , around the globe, is a rare surname. The last name ทอนใจ is habitual in Israel, where it is a rare surname, Myanmar, and Thailand, where it is a very rare surname. Not in comparison with a country's population, it is the most numerous in Myanmar, Thailand, and China. Very seldom, ทอนใจ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Regret | Indonesia, China, South Africa, France, Myanmar |
| ทอนใจ | Thailand |