Bielefeld's 2021 population is now estimated at 334,475. In 1950, the population of Bielefeld was 261,550. Bielefeld has grown by -14 since 2015, which represents a -0.00% 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 Bielefeld, which typically includes Bielefeld's population in addition to adjacent suburban areas.