Charlton is a town in Worcester County, Massachusetts, United States. The population was 12,981 at the 2010 census.HistoryCharlton was first settled in 1735. It was established as a District separated off from Oxford on January 10, 1755, and became a Town in 1775 by a law that made all Districts into Towns. It was named after Sir Francis Charlton. During the 1800s, farming continued to be the major occupation, but woolen mills were being built along some of the town's brooks by the turn of the twentieth century.GeographyAccording to the United States Census Bureau, the town has a total area of 43.8sqmi, of which 42.5sqmi is land and 1.2sqmi (2.86%) is water.The town is bordered on the west by Sturbridge; on the north by East Brookfield, Spencer and Leicester; on the east by Oxford; and on the south by Dudley and Southbridge.Charlton is bisected by north-south Route 31, which runs through the historical villages of Charlton Center, Charlton City and Charlton Depot. North-south Route 169 connects Charlton City with Southbridge. East-west routes include Route 20, a major commuter road, and the Massachusetts Turnpike (Interstate 90), which crosses through Charlton but does not have an exit in the town. While there is no exit for the town, there are two rest stops on the Mass Pike that are in Charlton.