Glen Rock 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 12,133, an increase of 532 from the 2010 census count of 11,601, which in turn reflected increased by 55 from the 11,546 counted in the 2000 census. The borough has been one of the state's highest-income communities.