Greenwich is an unincorporated community and census-designated place (CDP) in Cumberland County, in the U.S. state of New Jersey. It is in the western part of the county, in the southeast part of Greenwich Township, on the northwest side of the tidal Cohansey River, 4 miles (6 km) northeast of its mouth at Delaware Bay. The community is 7 miles (11 km) southwest of Bridgeton, the county seat.