Family name Simmawan (Simmawan 
) , in all the world, is a very rare cognomen. The last name Simmawan is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Simmawan | Thailand |
Phawat, Nittaya, Seangsuree, Nutthasit, and Natthapong