Surname Saythavy (Saythavy 
) , throughout the world, is a rare family name. The cognomen Saythavy is characteristic of Laos, where it is quite a rare surname, Lithuania, where it is a rare surname, and Canada, where it is a very rare surname. In absolute terms, it is the most numerous in Laos, the United States, and Lithuania.
| VARIANT | COUNTRY |
|---|---|
| Saythavy | Laos, Thailand, United States, Canada, Lithuania |