With 4 942 669 bearers, Sergey is the 1st most common masculine name in Russia (2014 Data). With 299 527 bearers, Sergey is the 3rd most common masculine name in Belarus (2014 Data). With 289 903 bearers, Sergey is the 2nd most common masculine name in Kazakhstan (2014 Data). With 18 061 bearers, Sergey is the 1st most common masculine name in Transnistria (2014 Data).Source: https://forebears.io/forenames/sergey