Riverside was incorporated as a borough by an Act of the New Jersey Legislature on June 30, 1894, as the Borough of Riverside from portions of Midland Township, at the height of the "Boroughitis" phenomenon then sweeping through Bergen County, based on the results of a referendum held the previous day. On December 1, 1930, the borough's name was changed to River Edge.
As of the census of 2000, there were 10,946 people, 4,165 households, and 3,102 families residing in the borough. The population density was 5,804.5 people per square mile (2,236.1/km). There were 4,210 housing units at an average density of 2,232.5/sq mi (860.0/km). The racial makeup of the borough was 84.12% White, 1.06% African American, 0.08% Native American, 12.60% Asian, 0.01% Pacific Islander, 0.81% from other races, and 1.32% from two or more races. Hispanic or Latino of any race were 5.31% of the population.
There were 4,165 households out of which 35.0% had children under the age of 18 living with them, 64.4% were married couples living together, 7.6% had a female householder with no husband present, and 25.5% were non-families. 22.7% of all households were made up of individuals and 11.5% had someone living alone who was 65 years of age or older. The average household size was 2.62 and the average family size was 3.11.
In the borough the population was spread out with 24.1% under the age of 18, 5.0% from 18 to 24, 30.2% from 25 to 44, 23.8% from 45 to 64, and 17.0% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 90.9 males. For every 100 females age 18 and over, there were 86.7 males.
The median income for a household in the borough was $71,792, and the median income for a family was $80,422. Males had a median income of $62,044 versus $41,085 for females. The per capita income for the borough was $33,188. About 2.5% of families and 3.1% of the population were below the poverty line, including 3.5% of those under age 18 and 2.6% of those age 65 or over.
River Edge has two separate stations on New Jersey Transit's Pascack Valley Line. The two stations are River Edge (at River Edge Road on the north end of town) and North Hackensack (at Grand Street on the south end of town).
This line runs north-south to Hoboken Terminal with connections to the PATH train from the Hoboken PATH station and New Jersey Transit service to New York Penn Station via the Secaucus Junction transfer station. Connections are also available at the Hoboken Terminal to NY Waterway ferry service to the World Financial Center and other destinations.
New Jersey Transit also offers bus service to the Port Authority Bus Terminal in Midtown Manhattan on the 165 route. The 11A route of Rockland Coaches also serves the Port Authority Bus Terminal.
Route 4 and County Route 503 passes through River Edge.