Diwaniyah's 2026 population is now estimated at 630,009. In 1950, the population of Diwaniyah was 22,854. Diwaniyah has grown by 19,205 in the last year, which represents a 3.14% 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 Diwaniyah, which typically includes Diwaniyah's population in addition to adjacent suburban areas.