Born in Vitebsk, Samoilau competed professionally for Acqua & Sapone–Caffè Mokambo between 2007 and 2008, a brief stint for Amica Chips–Knauf in 2009, for Quick-Step in 2009 and 2010, the Movistar Team in 2011 and 2012 and CCC–Polsat–Polkowice between 2014 and 2017.

Samoilau won the Belarusian National Road Race Championships in 2007.

He was national time trial champion of Belarus in 2009, 2010 and 2012.

Samoilau did not compete in the professional peloton in 2013, but joined CCC–Polsat–Polkowice for the 2014 season.

[2] During the 2015 Tour of Austria, Samoilau was fined a month's salary by his team for having said "fucking nigger" to Natnael Berhane, a black rider from Eritrea.