North Caldwell is a borough in northwestern Essex County, in the U.S. state of New Jersey, and a suburb of New York City. As of the 2020 United States census, the borough's population was 6,694, an increase of 511 from the 2010 census count of 6,183, which in turn reflected a decline of 1,192 from the 7,375 counted in the 2000 census. North Caldwell was incorporated by an act of the New Jersey Legislature on March 31, 1898, from portions of Caldwell Township.