Santiago's 2026 population is now estimated at 21,185. In 2000, the population of Santiago was 21,777. Santiago experienced a decrease of -264 residents over the past year, marking an annual decline of -1.23%. These population values and projections come from Panama census 2000 nomenclature places, Panama census 2010 nomenclature places, Panama census 2023 Cuadro 3 place population and World Population Review Internal Projections .