Cumberland County is a coastal county located on the Delaware Bay in the Southern Shore Region of the U.S. state of New Jersey. As of the 2020 census, the county was the state's 16th-most-populous county, with a population of 154,152, a decrease of 2,746 (−1.8%) from the 2010 census count of 156,898. Its county seat is Bridgeton. Cumberland County is named for Prince William, Duke of Cumberland. The county was formally created from portions of Salem County on January 19, 1748. The county is part of the South Jersey region of the state.

South Jersey comprises the southern portion of the U.S. state of New Jersey. It is located between Pennsylvania and the lower Delaware River to its west, the Atlantic Ocean to its east, Delaware to its south, and Central Jersey or North Jersey to its north, depending on the definition of North Jersey.