Brookline is a town in Hillsborough County, New Hampshire, United States. The population was 4,991 at the 2010 census. Brookline is home to the Talbot-Taylor Wildlife Sanctuary, Potanipo Pond, and the Brookline Covered Bridge.
According to the United States Census Bureau, the town has a total area of 20.1 square miles (52 km), of which 19.8 sq mi (51 km) is land and 0.4 sq mi (1.0 km) is water, comprising 1.79% of the town. The town’s highest point is the western summit of Birch Hill, at 810 feet (250 m) above sea level. Potanipo Hill is a 613-foot-high (187 m) summit southwest of the town center that once was the site of a ski area from 1935 to 1984, and now is home to Andres Institute of Art.
Brookline is drained by the Nissitissit River and Spaulding Brook. The 10-mile-long (16 km) Nissitissit is known for its abundance of trout. The Nissitissit begins at the outlet of Potanipo Pond, ⁄2 mile (0.8 km) west of the town center. Brookline lies within the Merrimack River watershed. The town is crossed by New Hampshire Route 13 and New Hampshire Route 130. It is about 12 miles (19 km) west of Nashua and approximately 50 miles (80 km) northwest of Boston, Massachusetts.
As of the census of 2000, there were 4,181 people, 1,343 households, and 1,146 families residing in the town. The population density was 211.5 people per square mile (81.7/km²). There were 1,384 housing units at an average density of 70.0 per square mile (27.0/km²). The racial makeup of the town was 97.87% White, 0.14% African American, 0.19% Native American, 0.62% Asian, 0.05% Pacific Islander, 0.22% from other races, and 0.91% from two or more races. Hispanic or Latino of any race were 0.91% of the population.
There were 1,343 households out of which 51.9% had children under the age of 18 living with them, 76.7% were married couples living together, 5.7% had a female householder with no husband present, and 14.6% were non-families. 10.6% of all households were made up of individuals and 3.1% had someone living alone who was 65 years of age or older. The average household size was 3.11 and the average family size was 3.36.
In the town, the population was spread out with 33.6% under the age of 18, 4.0% from 18 to 24, 35.7% from 25 to 44, 21.6% from 45 to 64, and 5.0% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 102.8 males. For every 100 females age 18 and over, there were 98.6 males.
The median income for a household in the town was $77,075, and the median income for a family was $80,214. Males had a median income of $55,417 versus $32,750 for females. The per capita income for the town was $29,272. About 0.9% of families and 0.8% of the population were below the poverty line, including 0.9% of those under age 18 and none of those age 65 or over.