[8] Dmitry Kozak was born on 7 November 1958 in the village of Bandurove, in the Kirovohrad region of the Ukrainian Soviet Socialist Republic (part of the USSR).

[12] Kozak worked as a public prosecutor in Leningrad and after the collapse of the Soviet Union, holding various legal offices in the city's administration.

[14] In 2003, he briefly entered international politics and unsuccessfully attempted to solve the conflict between Transnistria and Moldova (see Kozak memorandum).

[15][16][17] In September 2004, Kozak was appointed Presidential Plenipotentiary Envoy to the Southern Federal District, replacing Vladimir Yakovlev.

[18][19] On 24 September 2007, he was appointed to the new Russian cabinet headed by Viktor Zubkov as regional development minister, succeeding Vladimir Yakovlev again, and leaving his previous position.

On 15 January 2020, he resigned as part of the cabinet, after President Vladimir Putin delivered the Presidential Address to the Federal Assembly, in which he proposed several amendments to the constitution.

[10][22] On the first day of Russian's invasion of Ukraine in 2022, Kozak rang Zelensky aid Andrii Yermak stating it was time for Ukrainians to surrender.

[28][29][30] On 29 April 2014, Kozak was added to the European Union sanctions list due to his role in the annexation of Crimea by the Russian Federation.