North Arlington was formed by a referendum passed on March 9, 1896, and incorporated as a borough by an Act of the New Jersey Legislature on March 11, 1896, from area taken from Union Township.
As of the census of 2000, there were 15,181 people, 6,392 households, and 4,129 families residing in the borough. The population density was 5,880.7 people per square mile (2,271.9/km²). There were 6,529 housing units at an average density of 2,529.2/sq mi (977.1/km²). The racial makeup of the borough was 89.61% White, 0.46% African American, 0.14% Native American, 5.61% Asian, 0.01% Pacific Islander, 2.29% from other races, and 1.87% from two or more races. Hispanic or Latino of any race were 10.57% of the population.
There were 6,392 households out of which 24.5% had children under the age of 18 living with them, 49.7% were married couples living together, 11.1% had a female householder with no husband present, and 35.4% were non-families. 30.9% of all households were made up of individuals and 14.3% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 3.00.
In the borough the population was spread out with 18.0% under the age of 18, 7.6% from 18 to 24, 30.8% from 25 to 44, 24.2% from 45 to 64, and 19.4% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 88.7 males. For every 100 females age 18 and over, there were 84.1 males.
The median income for a household in the borough was $51,787, and the median income for a family was $62,483. Males had a median income of $41,512 versus $34,769 for females. The per capita income for the borough was $24,441. About 3.4% of families and 5.1% of the population were below the poverty line, including 6.2% of those under age 18 and 6.1% of those age 65 or over.
Route 7 and Route 17 both pass through North Arlington, meeting at the intersection of Ridge Road (Rt. 17) and the Belleville Turnpike (Rt. 7).
New Jersey Transit bus routes 39, 40 and 76 serve North Arlington.