Family name สายยะวงศ์ (สายยะวงศ์ 
, Saiyavong 
) , all over the world, is a rare surname. The cognomen สายยะวงศ์ is characteristic of Laos, where it is quite a common surname, Thailand, where it is a rare surname, and France, where it is an extremely rare surname. Not in comparison with a country's population, this name is the most popular in Laos, Thailand, and the United States.
| VARIANT | COUNTRY |
|---|---|
| สายยะวงศ์ | Thailand |
| Saiyavong | Canada, France, United States, Thailand, Laos |