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