Milford is a town in Hillsborough County, New Hampshire, United States, on the Souhegan River. The population was 13,575 at the 2000 census. It is the retail and manufacturing center of a six-town area known informally as the Souhegan Valley. The town center of Milford, where over 61% of the population resides, is defined as the Milford census-designated place (CDP), and is located at the junction of New Hampshire routes 13 and 101A.