Surname คำธร (Dharma 
, Khamtorn 
, คำธร) , globally, is a common family name. The surname คำธร is habitual in Indonesia, where it is quite a common surname, Qatar, where it is quite a rare surname, and United Arab Emirates. In absolute terms, it is commonest in Indonesia, India, and Nepal. More frequently, คำธร is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Dharma | Saudi Arabia, Nepal, India, Sri Lanka, Indonesia |
| Khamtorn | Thailand |