Brentwood is a town in Rockingham County, New Hampshire, United States. As of the 2010 census, the town had a total population of 4,486. Brentwood has been the county seat of Rockingham County since 1997.
Brentwood is a nearly square quadrangle, except that the town line follows the Exeter River in the southeast corner.
Brentwood has a total area of 17.0 square miles (44.0 km), of which 16.8 square miles (43.4 km) is land and 0.23 square miles (0.6 km) is water, comprising 1.30% of the town. The highest point in Brentwood is Great Hill, at 275 feet (84 m) above sea level, whose summit is in the southeast corner of the town.
The town is drained by the Exeter River and its tributaries, the Piscassic and Little rivers. Brentwood lies fully within the Piscataqua River (Coastal) watershed.
As of the census of 2010, there were 4,486 people, 1,319 households, and 1,087 families residing in the town. The population density was 267.0 people per square mile (103.4/km²). There were 1,350 housing units at an average density of 80.4 per square mile (31.1/km²). The racial makeup of the town was 96.3% White, 0.7% African American, 0.1% Native American, 1.0% Asian, 0.1% Pacific Islander, 0.5% some other race, and 1.3% from two or more races. Hispanic or Latino of any race were 1.5% of the population.
There were 1,319 households, out of which 46.2% had children under the age of 18 living with them, 71.6% were headed by married couples living together, 7.1% had a female householder with no husband present, and 17.6% were non-families. 14.0% of all households were made up of individuals, and 5.9% were someone living alone who was 65 years of age or older. The average household size was 3.02, and the average family size was 3.33.
In the town, the population was spread out with 26.6% under the age of 18, 7.2% from 18 to 24, 24.0% from 25 to 44, 28.8% from 45 to 64, and 13.4% who were 65 years of age or older. The median age was 41.1 years. For every 100 females, there were 106.1 males. For every 100 females age 18 and over, there were 106.6 males.
For the period 2007-2011, the estimated median annual income for a household in the town was $110,250, and the median income for a family was $111,650. Male full-time workers had a median income of $69,565 versus $55,000 for females. The per capita income for the town was $37,385. About 1.0% of families and 2.2% of the population were below the poverty line, including 3.2% of those under age 18 and 0.4% of those age 65 or over.
Brentwood New Hampshire neighborhoods include: Deerhill Estates, The Meadows, Washington Dr