Cognomen Sungyoun (Sungyoun 
) , across the world, is a very rare family name. The last name Sungyoun is characteristic of Thailand, where it is an extremely rare surname, and China. Much more prevalently, Sungyoun is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sungyoun | Thailand, South Korea, Brazil, United States, China |