Passaic County is a county in the U.S. state of New Jersey that is part of the New York metropolitan area. As of the 2020 United States census, the county was the state's eighth-most-populous county, with a population of 524,118, its highest decennial count ever and an increase of 22,892 from the 2010 census count of 501,226, which in turn reflected an increase of 12,177 from the 489,049 counted in the 2000 census. From Wikipedia