Udon Thani's 2025 population is now estimated at 604,163. In 1950, the population of Udon Thani was 16,129. Udon Thani has grown by 7,093 in the last year, which represents a 1.19% 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 Udon Thani, which typically includes Udon Thani's population in addition to adjacent suburban areas.