Passaic is a city in Passaic County, in the U.S. state of New Jersey. As of the 2020 United States census, the city was the state's 16th-most-populous municipality, with a population of 70,537, falling behind Bayonne, an increase of 756 from the 2010 census count of 69,781, which in turn reflected an increase of 1,920 residents from the 2000 census population of 67,861.