Family name Сиюан (Siyuan 
, Sijuan 
, Сиюан 
) , across the world, is a rare last name. The family name Сиюан is habitual in Singapore, where it is a rare surname, Malaysia, where it is a very rare surname, and China. Predominantly, Сиюан is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Siyuan | China, Australia, Singapore, Taiwan, United States |
| Sijuan | China, Malaysia, Brazil, United States |
| Сиюан | Russia |
| Syyuan | United States |