Hillsborough, frequently spelled Hillsboro, is a town in Hillsborough County, New Hampshire, United States. The population was 6,011 at the 2010 census. The town is home to Fox State Forest and part of Low State Forest.
The main village of the town, where 1,976 people resided at the 2010 census, is defined as the Hillsborough census-designated place (CDP), and encompasses the central urban area of the town, located along the Contoocook River at the junction of New Hampshire Route 149 with Henniker Street and Main Street. The town also includes the villages of Hillsborough Center, Hillsborough Upper Village, Hillsborough Lower Village, and Emerald Lake Village.
The town was first granted in 1735 by Colonial Governor Jonathan Belcher as "Number Seven," one in a line of nine towns set up as defense barriers against Indian attacks. The towns were renamed following the 1741 establishment of New Hampshire as a separate province. Settled in 1741, the town was granted in 1748 by Governor Benning Wentworth as "Hillsborough," named for Sir Wills Hill, Earl of Hillsborough. It would be incorporated in 1772 by Governor John Wentworth.