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