Hillsborough, frequently spelled Hillsboro, is a town in Hillsborough County, New Hampshire, USA. The population was 4,928 at the 2000 census. It includes Hillsborough Center, the Upper Village and the Lower Village. The town is home to Fox State Forest and part of Low State Forest. Hillsborough apartments for rent comparison page shows most up to date rent information on Hillsborough apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.