Mantua Township is a township in Gloucester County, New Jersey, United States. As of the 2010 United States Census, the township's population was 15,217, reflecting an increase of 1,000 from the 14,217 counted in the 2000 Census, which had in turn increased by 4,143 from the 10,074 counted in the 1990 Census.Mantua Township was formed as a township by an act of the New Jersey Legislature on February 23, 1853, from portions of Greenwich Township. Portions of the township were taken to form East Greenwich Township and Pitman. The township is named after Mantua, in Italy or for a Mantua sub-tribe of the Lenape Native Americans.