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