In the entire world, Seguei (Сегей 
, Сегеи , Seguei 
) is a rare masculine forename. The first name Seguei is habitual in Slovakia, where it is a rare masculine name, Russia, and Kazakhstan. Much less frequently, Seguei is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Сегей | Kazakhstan, Russia, Kyrgyzstan, Belarus, Ukraine |
| Сегеи | Russia |
| Seguei | Slovakia, United States, Spain, France |