San Antonio's 2026 population is now estimated at 7,916. In 2000, the population of San Antonio was 1,138. San Antonio has grown by 386 in the last year, which represents a 5.13% annual change. 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 .