Surname Siarhei (Сергей 
, Siarhei 
, セルゲイ 
) , throughout the world, is a widespread cognomen. The last name Siarhei is habitual in Armenia, where it is a common surname, Kyrgyzstan, and Moldova (explore the name in all countries). In absolute terms, the name is most common in Russia, Kyrgyzstan, and Belarus. Predominantly, Siarhei is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Сергей | Azerbaijan, Kazakhstan, Russia, Belarus, Ukraine |
| Siarhei | Romania, Russia, Belarus, United States, Poland |
| セルゲイ | Japan |
| سياري | Iran, Tunisia, Palestinian Territory, Algeria, Iraq |
Serge, Sergei, Sergej, Sergejs, Sergejus, Sergey, Serghei, Sergi, Sergio, Sergios, Sergiu, Sergius, Sergiusz, Serguei, Sergueï, Serguéi, Serhij, Serxio, Siarhej, Siarhiej, Siergiej, Syarhey, Szergej, Sérgio, Σέργιος, Сергий, Сергиос, Сергиус, Сергиуш, Сергій, Серджо, Серджу, Серж, Сержи, Сержио, Сержиу, Серхи, Серхио, Серый, Серёга, Сиаргеи, Сиархеи, Сиархей, Сяргей, Сярхеи, Сярхей, Сіаргей, סרג'י, סרגיוס, סרגיי, سرجيوس, سيارى, سيرج, سيرجي, سيرجيو, سيرغي, セルジョ, and セルヒオ
Manko, Bobrykau, Karaliou, Piletski, Ramaniuk, Druhakou, Dzenisevich, Lahvinets, Lepchankou, Zavadski, Zhurkevich, Shakhlevich, Stsepanenka, Barkouski, Karpinchyk, Karpovich, Kalamytsau, Khaletski, Kuzniatsou, Liakhovich, Yanushevich, Yakubouski, Babashynski, Ausiankin, Asipenka, Spirydovich, Novik, Shkoda, Slinko, Bubnou, Kazlou, Kuryla, Protas, Ivanou, Miadzvezhanka, Slizheuski, Yarashevich, Antonik, Kastrykin, Kozyrau, Horbach, Yakauleu, Zaitsau, Melnikau, Murauyou, Sadouski, Savitski, Shauchuk, Barysau, and Herasimovich