Newington is a town in Rockingham County, New Hampshire, United States. The population was 753 at the 2010 census. It is bounded to the west by Great Bay, northwest by Little Bay and northeast by the Piscataqua River. It is home to Portsmouth International Airport at Pease (formerly Pease Air Force Base), and to the New Hampshire National Guard. The 110-acre (45 ha) Old Town Center Historic District is listed on the National Register of Historic Places.
According to the United States Census Bureau, the town has a total area of 12.5 square miles (32.4 km), of which 8.2 square miles (21.2 km) is land and 4.2 square miles (10.9 km) is water, comprising 34.25% of the town. The highest elevation in Newington is 130 feet (40 m) above sea level, near Newington Cemetery.
The town is crossed by U.S. Route 4 and New Hampshire Route 16.
As of the census of 2000, there were 775 people, 294 households, and 209 families residing in the town. The population density was 92.7 people per square mile (35.8/km²). There were 305 housing units at an average density of 36.5 per square mile (14.1/km²). The racial makeup of the town was 96.00% White, 1.81% African American, 0.26% Native American, 1.03% Asian, and 0.90% from two or more races. Hispanic or Latino of any race were 1.81% of the population.
There were 294 households out of which 28.2% had children under the age of 18 living with them, 59.5% were married couples living together, 6.8% had a female householder with no husband present, and 28.9% were non-families. 21.8% of all households were made up of individuals and 8.2% had someone living alone who was 65 years of age or older. The average household size was 2.55 and the average family size was 3.01.
In the town, the population was spread out with 21.9% under the age of 18, 4.6% from 18 to 24, 28.4% from 25 to 44, 32.1% from 45 to 64, and 12.9% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 98.7 males. For every 100 females age 18 and over, there were 93.9 males.
The median income for a household in the town was $59,464, and the median income for a family was $76,202. Males had a median income of $48,750 versus $30,250 for females. The per capita income for the town was $30,172. About 5.0% of families and 4.6% of the population were below the poverty line, including 4.8% of those under age 18 and 5.3% of those age 65 or over.