Clifton is a city in Passaic County, New Jersey, United States. As of the 2010 United States Census, the city had a total population of 84,136, retaining its position as the state's 11th-largest municipality, as the population increased by 5,464 (+6.9%) from the 78,672 counted in the 2000 Census, which had in turn increased by 6,930 (+9.7%) from the 71,742 counted in the 1990 Census.