Sergey Rozhnov (Bulgarian: Сергей Рожнов; born 19 September 1982 in Moscow, Russia) is a Russian former professional boxer who competed during 2012.

He defeated former heavyweight world title challenger Owen Beck in his only professional bout.

There he was stopped in the first round of the Super heavyweight (+91 kg) division by Russia's eventual winner Alexander Povetkin.

Rozhnov won a bronze medal in the same division six months earlier, at the 2004 European Amateur Boxing Championships in Pula, Croatia.

This biographical article related to a Bulgarian boxer is a stub.