Semipalatinsk's 2023 population is now estimated at 322,125. In 1950, the population of Semipalatinsk was 134,266. Semipalatinsk has grown by 904 in the last year, which represents a 0.28% 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 Semipalatinsk, which typically includes Semipalatinsk's population in addition to adjacent suburban areas.