Sanford is a town in York County, Maine, United States. The population was 20,798 in the 2010 census, making it the seventh largest municipality in the state, and the largest town (not city) in the state. Situated on the Mousam River, Sanford includes the village of Springvale. The town features many lakes in wooded areas which attract campers. Sanford is part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area.