Tainan's 2025 population is now estimated at 880,865. In 1950, the population of Tainan was 40,000. Tainan has grown by 5,473 in the last year, which represents a 0.63% 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 Tainan, which typically includes Tainan's population in addition to adjacent suburban areas.