San Juan Antiguo (not to be confused with the historic district of Old San Juan which is located within this district), is a barrio located in the municipality of San Juan in the Commonwealth of Puerto Rico. San Juan Antiguo has 7 subbarrios. In 2020, San Juan Antiguo had a population of 6,383 inhabitants and a population density of 2,400 people per km2. San Juan Antiguo is entirely located within the Isleta de San Juan, the islet off the coast of Puerto Rico where Old San Juan was settled, connected to the mainland by bridges and a causeway.