Greenwich Township (pronounced "Green-witch") is a township in Cumberland County, New Jersey, United States. As of the 2010 United States Census, the township's population was 804, reflecting a decline of 43 (-5.1%) from the 847 counted in the 2000 Census, which had in turn declined by 64 (-7.0%) from the 911 counted in the 1990 Census. It is part of the Vineland-Millville- Bridgeton Primary Metropolitan Statistical Area for statistical purposes.
Greenwich Township was first formed as a precinct on January 19, 1748, and was incorporated by an Act of the New Jersey Legislature on February 21, 1798, as one of New Jersey's initial group of 104 townships. Portions of Hopewell Township and Stow Creek Township were annexed in 1845.