Hillsborough, frequently spelled Hillsboro, is a town in Hillsborough County, New Hampshire, United States. The population was 6,011 at the 2010 census. The town is home to Fox State Forest and part of Low State Forest.
According to the United States Census Bureau, the town has a total area of 44.6 square miles (115.6 km), of which 43.6 sq mi (113.0 km) is land and 1.0 sq mi (2.6 km) is water, comprising 2.23% of the town. The town center, or census-designated place, has a total area of 1.6 sq mi (4.2 km).
The highest point in Hillsborough is Thompson Hill, at 1,768 feet (539 m) above sea level, in the northern part of town. Hillsborough is drained by the Contoocook River, in addition to Beard’s and Sand brooks. Part of Franklin Pierce Lake is in the southwest. The town lies fully within the Merrimack River watershed.
As of the census of 2010, there were 6,011 people, 2,392 households, and 1,614 families residing in the town. The population density was 137.9 people per square mile (53.2/km²). There were 2,896 housing units at an average density of 66.4 per square mile (25.6/km²). The racial makeup of the town was 96.4% White, 0.6% Black or African American, 0.3% Native American, 0.6% Asian, 0.03% Native Hawaiian or other Pacific Islander, 0.3% some other race, and 1.8% from two or more races. Hispanic or Latino of any race were 1.4% of the population.
There were 2,392 households, out of which 34.2% had children under the age of 18 living with them, 50.2% were headed by married couples living together, 11.6% had a female householder with no husband present, and 32.5% were non-families. 24.5% of all households were made up of individuals, and 8.5% were someone living alone who was 65 years of age or older. The average household size was 2.51, and the average family size was 2.98.
In the town, the population was spread out with 24.8% under the age of 18, 7.4% from 18 to 24, 27.1% from 25 to 44, 29.8% from 45 to 64, and 11.0% who were 65 years of age or older. The median age was 38.6 years. For every 100 females, there were 98.9 males. For every 100 females age 18 and over, there were 95.3 males.
For the period 2007–2011, the estimated median annual income for a household in the town was $54,386, and the median income for a family was $67,621. Male full-time workers had a median income of $43,583 versus $32,030 for females. The per capita income for the town was $23,232. About 7.1% of families and 11.2% of the population were below the poverty line, including 8.5% of those under age 18 and 6.5% of those age 65 or over.