Zelenin graduated from the Moscow Institute of Physics and Technology (Phystech) in 1986 and worked in the electronics industry until 1990 when he became commercial director of Resurs Bank and chief executive of this bank in 1995.

Zelenin was one of the top managers of Norilsk Nickel having joined in 1996 as first deputy general director.

Dmitry Zelenin was elected governor of Tver Oblast in December 2003, bypassing incumbent Vladimir Platov, MVD officer Igor Zubov and communist Tatyana Astrakhankina.

In 2010, Zelenin caused a scandal when he posted photos of a salad containing an earthworm on his Twitter account, which was allegedly served to German President Christian Wulff.

Sergei Prikhodko, foreign policy adviser to president Dmitry Medvedev, then asked him to resign.