Pennsville Township is a township in Salem County, in the U.S. state of New Jersey. The township is named for William Penn. It is the westernmost town in New Jersey. As of the 2020 United States census, the township's population was 12,684, a decrease of 725 (−5.4%) from the 2010 census count of 13,409, which in turn reflected an increase of 215 (+1.6%) from the 13,194 counted in the 2000 census.