Lancaster, New Hampshire, USA

Lancaster is a town located along the Connecticut River in Coös County, New Hampshire, United States. The town is named after the city of Lancaster in England. It is the county seat of Coos County and gateway to the Great North Woods Region of the state. Lancaster, which includes the villages of Grange and South Lancaster, is home to Weeks State Park and the Lancaster Fair. Part of the White Mountain National Forest is in the eastern portion.

The main village in town, where 1,941 people resided at the 2020 census, is defined as the Lancaster census-designated place and is located at the junctions of U.S. Route 3 and U.S. Route 2, along the Israel River.
Lancaster is the site of the "PorcFest", an annual festival of the Free State Project that draws thousands of visitors each year.

Lancaster is drained by the Israel River, and is fully within the Connecticut River watershed. The Connecticut River forms the northwest border of the town, as well as the border with Vermont. The town also includes Martin Meadow Pond. Lancaster's highest point is located on a western spur of Mount Cabot at 3,290 feet above sea level.