Cognomen 蔡昀 (蔡昀 
) , in the entire world, is a very rare family name. The family name 蔡昀 is habitual in Eastern Asia, particularly China, where it is an extremely rare surname. More prevalently, 蔡昀 is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| 蔡昀 | China |