Harrington Park is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 4,664, reflecting a decrease of 76 (-1.6%) from the 4,740 counted in the 2000 Census, which had in turn increased by 117 (+2.5%) from the 4,623 counted in the 1990 Census.
Harrington Park was formed on March 29, 1904, from portions of Harrington Township and Washington Township, and parts of the borough of Closter.
The name "Harrington Park" was based on the larger Harrington Township from which it was in part derived, which in turn was based on the family name Haring, who were early settlers of the region.
According to the United States Census Bureau, Harrington Park borough had a total area of 2.059 square miles (5.333 km2), including 1.832 square miles (4.745 km2) of land and 0.227 square miles (0.589 km2) of water (11.04%).
The borough borders Closter, Emerson, Norwood, Old Tappan and River Vale.
The 2010 United States Census counted 4,664 people, 1,592 households, and 1,327.728 families in the borough. The population density was 2,545.9 per square mile (983.0/km2). There were 1,624 housing units at an average density of 886.5 per square mile (342.3/km2). The racial makeup was 79.76% (3,720) White, 0.69% (32) Black or African American, 0.02% (1) Native American, 17.43% (813) Asian, 0.19% (9) Pacific Islander, 0.51% (24) from other races, and 1.39% (65) from two or more races. Hispanic or Latino of any race were 3.49% (163) of the population. Korean Americans accounted for 13.0% of the population.
Of the 1,592 households, 41.8% had children under the age of 18; 73.9% were married couples living together; 7.3% had a female householder with no husband present and 16.6% were non-families. Of all households, 14.6% were made up of individuals and 8.7% had someone living alone who was 65 years of age or older. The average household size was 2.93 and the average family size was 3.26. Same-sex couples headed 34 households in 2010, an increase more than five-fold from the 6 counted in 2000.
28.0% of the population were under the age of 18, 5.4% from 18 to 24, 18.3% from 25 to 44, 33.4% from 45 to 64, and 14.9% who were 65 years of age or older.