Madbury is a town in Strafford County, New Hampshire, United States. The population was 1,771 at the 2010 census.
The town of Madbury is shaped like a wedge, extending from the eastern tip of the town touching Cedar Point on Little Bay to the town’s border with Barrington to the west. According to the United States Census Bureau, the town has a total area of 12.2 square miles (32 km), of which 11.7 sq mi (30 km) is land and 0.6 sq mi (1.6 km) is water, comprising 4.58% of the town. The highest point of land is the summit of Hicks Hill, at 331 feet (101 m) above sea level, located close to the center of town.
Although a branch of the Oyster River rises in western Madbury, the Bellamy River is the only river of size in town. Bellamy Reservoir, fed by the Bellamy River together with Mallego Brook, covers 382 acres (1.5 km) and provides 60% of the water supply for Portsmouth. It was created in 1960 with a dam built by the Army Corps of Engineers.
Madbury is served by state routes 9, 108 and 155.
As of the census of 2000, there were 1,509 people, 534 households, and 411 families residing in the town. The population density was 129.2 people per square mile (49.9/km²). There were 543 housing units at an average density of 46.5 per square mile (17.9/km²). The racial makeup of the town was 96.62% White, 0.40% African American, 0.27% Native American, 1.26% Asian, 0.40% from other races, and 1.06% from two or more races. Hispanic or Latino of any race were 0.46% of the population.
There were 534 households out of which 42.3% had children under the age of 18 living with them, 63.1% were married couples living together, 9.6% had a female householder with no husband present, and 23.0% were non-families. 15.0% of all households were made up of individuals and 5.2% had someone living alone who was 65 years of age or older. The average household size was 2.83 and the average family size was 3.13.
In the town, the population was spread out with 30.0% under the age of 18, 6.4% from 18 to 24, 32.3% from 25 to 44, 23.7% from 45 to 64, and 7.6% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 99.6 males. For every 100 females age 18 and over, there were 97.2 males.
The median income for a household in the town was $57,981, and the median income for a family was $67,981. Males had a median income of $47,969 versus $30,000 for females. The per capita income for the town was $26,524. About 3.9% of families and 5.8% of the population were below the poverty line, including 4.1% of those under age 18 and 3.4% of those age 65 or over.