Southborough is a town in Worcester County, Massachusetts, United States. It incorporates the smaller villages of Cordaville, Fayville, and Southville. Its name is often informally shortened to Southboro, a usage seen on many area signs and maps. Its population was 8,781 at the 2000 census. Land use is primarily residential with substantial open space. A quarter of the town's area is flooded by the Sudbury Reservoir. Light industrial land use is concentrated along main roads, primarily Massachusetts Rte. 9, and there are several small business districts in the villages and along Rte. 9. Southborough was named Number 31 in the nation on CNN Money's 100 Best Places to Live in 2009.