Gloucester City is a city in Camden County, in the U.S. state of New Jersey. As of the 2020 United States census, the city's population was 11,484, an increase of 28 from the 2010 census count of 11,456, which in turn reflected a decline of 28 from the 11,484 counted in the 2000 census. It is located directly across the Delaware River from Philadelphia and the Port of Philadelphia.