Saco (pronounced /sɑːkoʊ/ sah-koh) is a city in York County, Maine, United States. The population was 18,482 at the 2010 census. It is home to Ferry Beach State Park, Funtown Splashtown USA, Thornton Academy, as well as General Dynamics Armament Systems (also known by its former name, Saco Defense), a subsidiary of the defense contractor General Dynamics. Saco sees much tourism during summer months, due to its amusement parks, Ferry Beach State Park, and proximity to Old Orchard Beach.
Saco is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area. Saco's twin-city is Biddeford.
This was territory of the Abenaki tribe whose fortified village was located up the Sokokis Trail at Pequawket (now Fryeburg). The township was granted in 1630 by the Plymouth Company to Thomas Lewis and Richard Bonython, and extended 4 miles (6.4 km) along the sea, by 8 miles (13 km) inland. Settled in 1631 as part of Winter Harbor (as Biddeford Pool was first known), it then included Biddeford. It would be reorganized in 1653 by the Massachusetts General Court as Saco.