Omsk, city, southwestern Siberia Russia, capital of Omsk Oblast, at the confluence of the Irtysh and Om' rivers. The city is a major commercial and industrial center of the steppe region and is served by the Trans-Siberian Railroad. Manufactures include processed grain, refined petroleum, forest products, agricultural machinery, and textiles. Omsk was founded in 1716 as a Russian fortress. Following the Russian Revolution of 1917, the headquarters of the forces of Admiral Alexander V. Kolchak, the anti-Bolshevik leader, were located here. Population (1999 estimate) 1,157,600.
