Sergei Kharitonov (Sergey Haritonov, Russian (born August 18 , 1980) is a Russian heavyweight mixed martial artist. He has previously fought in Japanese MMA organization PRIDE Fighting Championships, and is now scheduled to fight for DREAM.

Sergei Kharitonov was born on August 18, 1980 in Arkhangelsk, Russia. His parents were very athletic: Sergei's mother was a volleyball coach, and his father at various times studied boxing, skating, soccer, and long distance marathon running. Under their influence, Sergei was very active physically while growing up.

Kharitonov graduated from a high school with a specialization in music (accordion). Following the advice of his parents as well as his own dreams, Sergei went to the Airborne troops academy in Ryazan, Russia, and enlisting in the Russian Airborne Troops after finishing the academy. Kharitonov credits the army and the academy with giving him psychological skills he relies on during his fights.

Sergei remains on the active duty while training full time with the Russian Top Team. He is married to his wife, Natalia.

Sergei is supposedly having a feud with Fedor Emelianenko after Fedor transferred from Russian Top Team to Red Devil Sport Club, and Kharitonov decided to stay with RTT.

Kharitonov sometimes gets confused with his full namesake Sergey Haritonov, a much less prominent mixed martial arts fighter from Estonia.

Sergei started being interested in sports when he was still in kindergarten, being taught at first by his father. Kharitonov started training boxing seriously when he was ten or eleven years old, following an incident when a drunken adult passer-by broke up a scuffle between Sergei and another boy by lifting Sergei in the air, hitting him in the face and cutting his eyebrow with that punch. The man justified his behavior by saying that Sergei should not have been hitting a grounded opponent.

At the age of sixteen, Kharitonov started studying Combat Sambo. During his studies in the Airborne Troops Academy, Sergei started competing in hand-to-hand combat (simplified form of Combat Sambo) and MMA. After Kharitonov graduated from the Academy, he was contacted by Vladimir Pogodin, the manager of the Russian Top Team, who invited him to join the club.

At first, Sergei was invited to be Fedor Emelianenko's sparring partner, who taught him many ground fighting techniques, including striking on the ground and submissions. Sergei kept competing at various Russian MMA competitions, and in October 2003 he debuted in PRIDE Fighting Championships, one of the top two leading MMA organizations in the world.

Sergei trains with the Russian national boxing and Sambo teams, as well as some freestyle wrestlers. He also recently added Muay Thai training to his regimen, and, according to him, he even borrows some elements from karate.

Sergei Kharitonov trained in Kirieevsk, Russia, under coach Mikhail Ilyukhin. Ilyukhin chose Kirieevsk as their training base due to a large number of heavyweight MMA fighters available there. According to him, key elements of Sergei's success are his willpower and unpredicability in the ring. As of September 2007 he recently began training with the Golden Glory fight team in Holland.

Sergei had a successful career as a heavyweight fighter in the PRIDE Fighting Championship, with an overall PRIDE record of 8-3-0. As of late 2005, Kharitonov has struggled with ongoing injuries to his upper back and shoulders, evident in his victory against Fabricio Werdum, in which his right shoulder was strained and injured nearly a minute into the bout, and in his loss to Alistair Overeem, where an awkward fall dislocated his shoulder.

Kharitonov lost to Aleksander Emelianenko at PRIDE's Final Conflict Absolute 2006 on Sept 9 2006.

Kharitonov scored a win against Mike Russow at PRIDE 33 in Las Vegas on February 24.

On September 17, 2007, Kharitonov knocked out Alistair Overeem in the first round in the K-1 HERO's event, subsequently avenging a previous loss.

Kharitonov's next fight was scheduled to be against Mighty Mo at DREAM.6 on September 23, 2008. However Mighty Mo was forced to withdraw due to a back injury. Jimmy Ambriz was Mighty Mo's replacement. Sergei scored a win in the first round by submission via strikes. Sergei' next fight is scheduled on April, 5th at next DREAM show.