Demarest is a Borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough population was 4,881.
Demarest was formed by an Act of the New Jersey Legislature on April 8, 1903, from portions of Harrington Township and Palisades Township. The borough was named for Ralph S. Demarest, who had represented the area in both the New Jersey General Assembly and the New Jersey Senate in the mid-19th century.
Demarest is located at 40°57′20″N 73°57′38″W / 40.955603°N 73.960446°W / 40.955603; -73.960446 (40.955603, -73.960446).