Sergei Muhhin (born 21 January 1990 in Tallinn) is an Estonian former competitive figure skater. As a single skater, he is the 2006 Estonian national champion. He switched to pair skating in 2009 and teamed up with Natalya Zabiyako. They are the 2010 Estonian champions. He is the younger brother of Jelena Muhhina, who also competed in figure skating.