Globally, Tretiakov (Третьяков 
, Третиаков , Tretiakov 
) is an extremely rare boy's given name. Much more prevalently, Tretiakov is the last name as well as the forename.
Mr, Vadim, Vladi, Illia, Youri, Yuriy, Maksim, Mykyta, Sergii, Sergey, Sergei, Serhii, Alexei, Alexey, Andres, Andrew, Andrei, Andrey, Andrii, Kumiko, Kirill, Daniel, Jorge, Danil, Denis, Roman, Max, Yra, Mark, Mike, Alex, Paul, Dima, Egor, Ilia, Ilya, Daniil, Ivan, Oleg, Yuri, Maxim, Moria, Alisa, Anton, Artem, Artur, Pavel, Peter, Igor, and Dmitri