Camden County is a county located in the U.S. state of New Jersey. Its county seat is Camden. As of the 2020 census, the county was the state's ninth-most populous county, with a population of 523,485, its highest decennial count ever and an increase of 9,828 from the 2010 census count of 513,657, which in turn reflected an increase of 4,725 from th…Camden County is a county located in the U.S. state of New Jersey. Its county seat is Camden. As of the 2020 census, the county was the state's ninth-most populous county, with a population of 523,485, its highest decennial count ever and an increase of 9,828 from the 2010 census count of 513,657, which in turn reflected an increase of 4,725 from the 508,932 counted in the 2000 census. The county is part of the South Jersey region of the state.