Teaneck ( /ˈtiːnɛk/) is a township in Bergen County, New Jersey, and a suburb in the New York metropolitan area. As of the 2010 United States Census, the township population was 39,776, making it the second-most populous among the 70 municipalities in Bergen County.

Teaneck was created on February 19, 1895 by an Act of the New Jersey Legislature. Teaneck was formed from portions of Englewood Township and Ridgefield Township, both of which are now defunct (despite existing municipalities with similar names), along with portions of Bogota and Leonia. Independence followed the result of a referendum held on January 14, 1895, in which voters favored incorporation by a 46–7 margin. To assuage the concerns of Englewood Township's leaders, the new municipality was formed as a township, rather than succumbing to the borough craze sweeping across Bergen County at the time. On May 3, 1921, and June 1, 1926, portions of what had been Teaneck were transferred to Overpeck Township.

Teaneck lies at the junction of Interstate 95 and the eastern terminus of Interstate 80. It is bisected into north and south portions by Route 4 and east and west by the CSX Transportation River Subdivision. Commercial development is concentrated in four main shopping areas, on Cedar Lane, Teaneck Road, DeGraw Avenue, West Englewood Ave. and Queen Anne Road, more commonly known as "The Plaza".