Chesterfield is a town in Cheshire County, New Hampshire, United States. The population was 3,604 at the 2010 census. It includes the villages of Spofford and West Chesterfield. Chesterfield is home to Spofford Lake, Chesterfield Gorge Natural Area, and parts of Pisgah State Park and Wantastiquet Mountain State Forest.
According to the United States Census Bureau, the town has a total area of 47.6 square miles (123 km), of which 45.6 sq mi (118 km) is land and 2.0 sq mi (5.2 km) (4.21%) is water. Chesterfield is bounded on the west by the Connecticut River. The highest point in the town is near its southern border, atop Davis Hill, at 1,427 feet (435 m) above sea level. Chesterfield lies fully within the Connecticut River watershed.
The town is served by state routes 9 and 63.
As of the census of 2000, there were 3,542 people, 1,366 households, and 1,005 families residing in the town. The population density was 77.7 people per square mile (30.0/km²). There were 1,632 housing units at an average density of 35.8 per square mile (13.8/km²). The racial makeup of the town was 97.80% White, 0.23% African American, 0.56% Native American, 0.17% Asian, 0.08% from other races, and 1.16% from two or more races. Hispanic or Latino of any race were 0.56% of the population.
There were 1,366 households out of which 32.7% had children under the age of 18 living with them, 63.5% were married couples living together, 6.9% had a female householder with no husband present, and 26.4% were non-families. 20.4% of all households were made up of individuals and 6.6% had someone living alone who was 65 years of age or older. The average household size was 2.59 and the average family size was 3.01.
In the town, the population was spread out with 25.9% under the age of 18, 4.9% from 18 to 24, 27.9% from 25 to 44, 30.4% from 45 to 64, and 10.9% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 103.8 males. For every 100 females age 18 and over, there were 100.2 males.
The median income for a household in the town was $51,351, and the median income for a family was $58,516. Males had a median income of $44,087 versus $26,547 for females. The per capita income for the town was $25,051. About 4.9% of families and 4.5% of the population were below the poverty line, including 4.5% of those under age 18 and 6.4% of those age 65 or over.