Ridgefield is a borough in Bergen County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 11,501, an increase of 469 from the 2010 census count of 11,032, which in turn reflected an increase of 202 from the 10,830 counted in the 2000 census. Ridgefield was incorporated as a borough by an act of the New Jersey Legislature on May 26, 1892, from portions of Ridgefield Township. The borough was named for the area's terrain.