Phra Nakhon Si Ayutthaya's 2026 population is now estimated at 476,244. In 1950, the population of Phra Nakhon Si Ayutthaya was 16,344. Phra Nakhon Si Ayutthaya has grown by 5,802 in the last year, which represents a 1.23% 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 Phra Nakhon Si Ayutthaya, which typically includes Phra Nakhon Si Ayutthaya's population in addition to adjacent suburban areas.