Pittsfield is a town in Merrimack County, New Hampshire, United States. The population was 4,075 at the 2020 census. The main village in town, where 1,570 people resided at the 2020 census, is defined as the Pittsfield census-designated place, and is located on the Suncook River in the west-central portion of town. It consists of the built-up village centered on the intersections of Barnstead Road, Catamount Road, Carroll Street, and Depot Street.