Kisumu's 2025 population is now estimated at 422,148. In 1950, the population of Kisumu was 12,103. Kisumu has grown by 15,464 in the last year, which represents a 3.8% 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 Kisumu, which typically includes Kisumu's population in addition to adjacent suburban areas.