San Pedro is a commune of the Melipilla Province in central Chile's Santiago Metropolitan Region. According to the 2002 census of the N…San Pedro is a commune of the Melipilla Province in central Chile's Santiago Metropolitan Region. According to the 2002 census of the National Statistics Institute, San Pedro spans an area of 787.5 km² and has 7,549 inhabitants, and the commune is an entirely rural area. The population grew by 11.9% between the 1992 and 2002 censuses.