Sergey Kazakov (born July 8, 1976) is a Russian amateur boxer best known to win the World Championships 2003 and European Championships 1998, 2002 and 2004 in the Men's Light Flyweight. Kazakov won the European Championships in 1998. In 2000 he lost at the European Championships to Valeriy Sydorenko in the finals and at the Olympics 2000 against reigning world champ Brian Viloria (6:8) in the first round. In 2003 he won the World Championships with a close final victory against future star Zou Shiming (23:19). He added a victory at the European championships 2002 and 2004 by beating Alfonso Pinto. 2004 at the Olympics he was upset by young Turk Atagün Yalçınkaya and had to settle for bronze. 2005 at the world championships he again lost to a teenager in Hungary's Pal Bedak. In 2005 he was part of the Russian team that won the Boxing World Cup.2007 he lost at the Russian Championships against David Ayrapetyan 9:25.