Omsk's 2025 population is now estimated at 1,180,820. In 1950, the population of Omsk was 444,326. Omsk has grown by 140 in the last year, which represents a 0.01% annual change.These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Omsk, which typically includes Omsk's population in addition to adjacent suburban areas.