Family name Sitthisa (Sitthisa 
) , in all the world, is a very rare cognomen. The family name Sitthisa is habitual in Thailand, where it is a very rare surname, and the United States, where it is an extremely rare surname. Very seldom, Sitthisa is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sitthisa | United States, Thailand |