Doku Umarov was born in April 1964 in the small village of Kharsenoi (Kharsenoy) in the southern Shatoysky District region of the Chechen–Ingush Autonomous Soviet Socialist Republic, into what he described as an intelligentsia family belonging the Malkoy teip (the same clan as the warlord Arbi Barayev and Chechnya's former foreign minister Ilyas Akhmadov). According to some sources, Umarov might have been convicted during his teenage years between 1980 and 1982 for either hooliganism, negligent homicide, or manslaughter. Umarov studied at the Oil Institute in Grozny, graduating with a degree in construction engineering. He later left the republic for the other parts of the Soviet Union and was reportedly working in the construction in Moscow when the First Chechen War began in December 1994. There were also reports that he was engaged in "semi-criminal activities" in Tyumen Oblast.

Umarov said he returned to Chechnya to fulfill what he called his patriotic duty. During the 1994–1996 war, he took part in the fighting against the intervention of Russian federal forces, initially serving under the command of Ruslan Gelayev in the special force popularly known as Gelayev's Spetsnaz (Gelayevskiy Spetsnaz). In 1996, Umarov left the unit because of disagreements with Gelayev and joined the command of Akhmed Zakayev, who had also left Gelayev's ranks to lead the splinter unit Wolf (Borz). In the course of the war, in which his unit was expanded into a battalion and then a regiment, Umarov was promoted to the rank of brigadier general and won two of Chechnya's highest awards for valor and bravery: Hero of the Nation (Kyoman Turpal) and Honor of the Nation (Kyoman Syi).

Following the Khasav-Yurt Accord that ended the war in 1996 and the presidential election of Aslan Maskhadov in January 1997, Umarov was named by Maskhadov to head the Chechen Security Council, tasked with helping to contain growing chaos in the ruined republic. In that position, he intervened in July 1998 to quash armed clashes between Chechen moderates and Islamic extremists in the city of Gudermes. However, Umarov was forced to resign from this post, and the Council was disbanded due to his failure to stabilise the situation in Chechnya and persistent rumors of his alleged participation in the practice of taking hostages for ransom (possibly in relationship with Arbi Barayev, who was widely accused of being a kidnapper).