Surname Сиаваш (Siavash 
, Syavash 
, Сиаваш 
) , throughout the world, is a rare family name. The family name Сиаваш is habitual in North Macedonia, where it is a rare surname, Iran, and Denmark, where it is a very rare surname. Measured by absolute frequency, this name is the most popular in Iran, China, and North Macedonia. Much more frequently, Сиаваш is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Siavash | Canada, Iran, Sweden, United States, Azerbaijan |
| Syavash | Canada, Iran, France, Spain, United States |
| Сиаваш | Russia, Ukraine |
| Siavach | Thailand |