As of the census of 2000, there were 60,695 people, 22,032 households, and 14,408 families residing in the township. The population density was 20,528.3 people per square mile (7,917.1/km²). There were 24,116 housing units at an average density of 8,156.5/sq mi (3,145.7/km²). The racial makeup of the township was 8.97% White, 81.66% African American, 0.24% Native American, 1.10% Asian, 0.10% Pacific Islander, 3.68% from other races, and 4.24% from two or more races. Hispanic or Latino of any race were 8.38% of the population.
As part of the 2000 Census, 81.66% of Irvington's residents identified themselves as being Black or African American. This was one of the highest percentages of African American and Caribbean American people in the United States, and the third-highest in New Jersey (behind Lawnside at 93.6%, and East Orange at 89.46%) of all places with 1,000 or more residents identifying their ancestry. Irvington also has a large Haitian-American population, with 5,812 persons claiming Haitian ancestry in the 2000 Census.
There were 22,032 households out of which 33.9% had children under the age of 18 living with them, 30.2% were married couples living together, 27.6% had a female householder with no husband present, and 34.6% were non-families. 29.3% of all households were made up of individuals and 6.4% had someone living alone who was 65 years of age or older. The average household size was 2.74 and the average family size was 3.39.
In the township the population was spread out with 28.0% under the age of 18, 10.7% from 18 to 24, 32.3% from 25 to 44, 21.5% from 45 to 64, and 7.5% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 87.7 males. For every 100 females age 18 and over, there were 81.5 males.
The median income for a household in the township was $36,575, and the median income for a family was $41,098. Males had a median income of $32,043 versus $27,244 for females. The per capita income for the township was $16,874. About 15.8% of families and 17.4% of the population were below the poverty line, including 22.9% of those under age 18 and 12.2% of those age 65 or over.
Irvington is served by New Jersey Transit bus routes 1, 13, 25, 26, 27, 37, 39, 42, 70, 90, 94, and 107.
Scheduled airline service is available at Newark Liberty International Airport in neighboring Newark and Elizabeth.