Swanzey is a town in Cheshire County, New Hampshire, United States. The population was 7,230 at the 2010 census. In addition to the town center, Swanzey includes the villages of East Swanzey, West Swanzey, North Swanzey and Westport.
First granted in 1733 as Lower Ashuelot, Swanzey was one of the fort towns established by Governor Jonathan Belcher of Massachusetts, which then claimed the territory. The town was the site of many battles during King George's War, and in 1747 was abandoned for three years. It was regranted to 62 proprietors on July 2, 1753 by Governor Benning Wentworth as Swanzey, most probably because some early settlers had a connection to Swansea in Wales. Situated on the Ashuelot River and connected by the Ashuelot Railroad, West Swanzey developed as a textile mill town, and East Swanzey produced wooden buckets for generations. By 1859, the population was 2,106.
The town features four covered bridges, and was the home of theatrical trouper Denman Thompson, who gained a national reputation by his portrayal of the Yankee farmer, "Joshua Whitcomb", star of his stage play The Old Homestead. Residents restage Thompson's melodrama every summer at a natural outdoor amphitheater called the Potash Bowl.
Because he vacationed in Swanzey during several summers, the town has claimed to be the location of a tree that inspired poet Joyce Kilmer (1886–1918) to write the popular 1913 poem "Trees". However, family accounts and documents establish that the poem was written in Mahwah, New Jersey.
According to the United States Census Bureau, the town has a total area of 45.3 square miles (117 km2), of which 45.0 sq mi (117 km2) is land and 0.4 sq mi (1.0 km2) is water, comprising 0.79% of the town.