Cognomen Сєргєй (Сєргєй 
) , in the world, is a very rare family name. The cognomen Сєргєй is habitual in Eastern Europe, particularly Ukraine, where it is a very rare surname. Also, Сєргєй is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Сєргєй | Ukraine |