Was born on August 18, 1959 in Leningrad.
After the termination in 1981 of the Leningrad institute of engineers of railway transport – the foreman of the shop of the Leningrad-Baltic locomotive depot of Oktyabrskaya Railway.
1983 - 1984 at Komsomol work in Leningrad. 1984 - 1990 service the officer in the Soviet Army, in army printing. 1990 - 1991 People's Deputy of Leningrad Soviet, head of the press center of Leningrad Soviet and Executive Committee of the City Soviet of People's Deputies. 1991 - 1996 the Chairman of the Committee on printing and mass media of the mayor's office of St. Petersburg, Mininformpechati's representative of the Russian Federation in the city and the Leningrad Region. 1996 - 1999 vice-chairman of the State committee of the Russian Federation on printing. 1999 doctoral candidate of MGIMO (U) of the Ministry of Foreign Affairs of the Russian Federation. 1999 – 2002 president of the Centre for Strategic Research (CSR), Moscow. 2002 – 2009 the member of the Federation Council of Federal Assembly of Russia - the representative from the Government of the Irkutsk region. 2002 - 2006 - the commission chairman of the Federation Council on information policy.
Since January, 2004 before granting of power to the Governor of the Irkutsk region - the Deputy Chairman of the Federation Council of Federal Assembly of Russia.
The chairman of the board of Business council of the Shanghai Cooperation Organization (on June 4, 2009 it is chosen repeatedly).
Member of Presidium of the State commission on issues of social and economic development of the Far East, Republic of Buryatia, Irkutsk region and Zabaykalsky Krai.
Member of Government Commission on High Technology and Innovation. The member of the commission at the President of Russia concerning development of information society. The member of council at the President of Russia on development of physical culture and sport, elite sport, preparation for holding the XXII Olympic Games and the XI Paralympic Winter Games 2014 in Sochi. Cochairman of Central Office of supporters of the United Russia Party. The candidate of psychological sciences (specialty – political psychology), the associate professor. The member of the Union of journalists of the USSR, Russia since January, 1988.
It is awarded with orders "For Merit to the Fatherland" 4th Class, Honour, the medal "For Construction of the Baikal-Amur Mainline", awarded ranks of the Officer of the State award of the Honourable Legion (France), other awards.
On June 8, 2009 on representation of the President of Russia Dmitry Medvedev at an extraordinary session deputies of Legislative assembly of the Irkutsk region unanimously gave to Dmitry Mezentsev the Governor's authority.
He is married, has the daughter.