Ridgefield is a borough in Bergen County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 11,032, reflecting an increase of 202 from the 10,830 counted in the 2000 Census, which had in turn increased by 834 from the 9,996 counted in the 1990 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.