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