Atco is an unincorporated community and census-designated place (CDP) in Waterford Township in Camden County, in the U.S. state of New Jersey. It is part of the Philadelphia-Camden metropolitan area, located 16 miles (26 km) southeast of Camden. Though generally considered part of Waterford Township, a small section of the southern edge of Atco is located in Winslow Township.

Waterford Township is a township in Camden County, in the U.S. state of New Jersey. As of the 2020 United States census, the township's population was 10,421, a decrease of 228 (−2.1%) from the 2010 census count of 10,649, which in turn reflected an increase of 155 (+1.5%) from the 10,494 counted in the 2000 census.