Sergei Duvanov, born 1953, is a prominent oppositional Kazakh journalist who in 2002 wrote articles that linked the President of Kazakhstan, Nursultan A Nazarbayev, to illicit Swiss bank accounts, creating a turmoil in the Central Asian country. The scandal was labeled Kazakhgate by some commentators.

Duvanov was arrested in October 2002 at his datcha outside Almaty, accused of raping a 14-year old girl, one day before a planned trip to the United States, where he was due to talk about Kazakhstan's human rights situation.

In January 2003 he was found guilty of the crime and sentenced to 3 1/2 years in prison.

Duvanov and the opposition claim that the case was politically motivated.