Milford is a town in Hillsborough County, New Hampshire, United States, on the Souhegan River. The population was 16,131 at the 2020 census, up from 15,115 at the 2010 census. It is the retail and manufacturing center of a multi-town area known informally as the Souhegan Valley. The town center, where 9,212 people lived at the 2020 census, is defined as the Milford census-designated place, and is located at the junction of New Hampshire routes 13 and 101A.