Oita's 2021 population is now estimated at 478,505. In 1950, the population of Oita was 81,791. Oita has grown by -754 since 2015, which represents a -0.16% 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 Oita, which typically includes Oita's population in addition to adjacent suburban areas.