Sergei Mureiko (born 2 July 1970) is a retired heavyweight Greco-Roman wrestler, who until 1996 represented Moldova and then Bulgaria. He competed in the 1996, 2000 and 2004 Olympics and won a bronze medal in 1996. Between 1993 and 2004 he won 11 medals at the world and European championships, often losing to his main rival Aleksandr Karelin.[2] He won his only international title in 1997, in the absence of Karelin. Karelin considered Mureiko one of his most difficult opponent.[3][4]