Family name Sysomboun (Sysomboun 
) , all around the world, is a rare last name. The cognomen Sysomboun is habitual in Laos, where it is quite a rare surname, Australia, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Sysomboun | Australia, Laos, United States |