Gloucester City is a city in Camden County, New Jersey, United States. As of the 2010 United States Census, the city's population was 11,456, reflecting a decline of 28 (-0.2%) from the 11,484 counted in the 2000 Census, which had in turn declined by 1,165 (-9.2%) from the 12,649 counted in the 1990 Census. It is located directly across the Delaware River from Philadelphia and the Port of Philadelphia.