Cognomen Seryj (Серый 
, Seryj 
) , worldwide, is quite a rare family name. The surname Seryj is characteristic of Belarus, where it is quite a rare surname, Russia, and Kazakhstan, where it is a rare surname. In absolute terms, it most frequently occurs in Eastern Europe, particularly Russia, Belarus, and Ukraine. Much less frequently, Seryj is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Серый | Kazakhstan, Belarus, Ukraine, Kyrgyzstan, Russia |
| Seryj | Czechia, Germany |