Family name ธรรมาสน์ (ธรรมาสน์ 
, Thammat 
, Pulphet) , in the world, is a very rare cognomen. The family name ธรรมาสน์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname. Much less frequently, ธรรมาสน์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| ธรรมาสน์, Thammasar | Thailand |
| Thammat | India, Thailand |
Thammakas, Thammakason, Thammanas, Thammasaard, Thammasack, Thammasad, Thammasanya, Thammasarat, Thammasat, Thammasattha, Thammasom, and Thammaxat