Clayton is a borough in Gloucester County in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 8,807, an increase of 628 (+7.7%) from the 2010 census count of 8,179, which in turn reflected an increase of 1,040 (+14.6%) from the 7,139 counted in the 2000 census.

Gloucester County is a county in the U.S. state of New Jersey. As of the 2020 census, the county was the state's 14th-most populous county with a population of 302,294, its highest decennial count ever and an increase of 14,006 (+4.9%) from the 288,288 counted in the 2010 census, which in turn represented an increase of 33,615 (+13.2%) from the 2000 census population of 254,673. Its county seat is Woodbury. The county is part of the South Jersey region of the state.