Belchertown (previously known as Cold Spring and Belcher's Town) is a town in Hampshire County, Massachusetts, United States. It is part of the Springfield, Massachusetts Metropolitan Statistical Area. The population was 14,649 at the 2010 census. It is the home of Belchertown High School and the infamous Belchertown State School mental institution which closed in 1992. Part of the town is part of the census-designated place of Belchertown.