Cognomen Yoonsung (Yoonsung 
) , around the globe, is a rare family name. The surname Yoonsung is habitual in South Korea, where it is a rare surname, Malaysia, where it is an extremely rare surname, and China. More prevalently, Yoonsung is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Yoonsung | South Korea, Malaysia, China, Canada, United States |