Cresskill is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 8,573, reflecting an increase of 827 (+10.7%) from the 7,746 counted in the 2000 Census, which had in turn increased by 188 (+2.5%) from the 7,558 counted in the 1990 Census. The community got its name from "Cress", referring to the watercress which grew in its streams, and "Kill", referring to the stream passing through.
Cresskill was incorporated as a borough by an Act of the New Jersey Legislature on May 8, 1894, from portions of Palisades Township. The borough was formed during the "Boroughitis" phenomenon then sweeping through Bergen County, in which 26 boroughs were formed in the county in 1894 alone. A portion of the borough was annexed by Alpine in 1904.
Railroads provided access from Cresskill to customers in New York City, including a chicken hatchery that was the world's largest by 1897. Railroad access helped make Cresskill the home of Camp Merritt, the major debarkation point for more than a million American troops being sent abroad to fight in World War I. A large obelisk memorial (referred to by locals as "The Monument"), or "The Circle Monument" was dedicated in 1924, set in the middle of the Camp Merritt Memorial Circle at the intersection of Madison Avenue and Knickerbocker Road (CR 505), to commemorate the fact.