Cognomen Suwannasay (Suwannasay 
) , in the world, is a very rare surname. The surname Suwannasay is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname.
| VARIANT | COUNTRY |
|---|---|
| Suwannasay | Thailand |
Somsak, Suttawadee, and Sutawadee