Surname ธรรมศาตร์ (ธรรมศาตร์ 
, Dhamasat 
, Thamasat ) , throughout the world, is a very rare family name. The cognomen ธรรมศาตร์ is characteristic of Thailand, where it is a very rare surname, and India, where it is an extremely rare surname. Much less frequently, ธรรมศาตร์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thamsaat, ธรรมศาตร์ | Thailand |
| Thamasat, Dhamasat | India, Thailand |
Thamasart, and Thammasatian