On November 20, 1824, the southern portion of Sussex County was set off to create Warren County. The northern portions of both Hardwick and Independence Townships remained in Sussex County and were incorporated as Green Township by an Act of the New Jersey Legislature on December 27, 1824. The township was named after Ephraim Green, who settled near Greendell in 1770. Many sections of Green retain their identity as Tranquility, Huntsville, Greendell, and Yellow Frame.
Green Township has an approximate total area of 16.256 square miles, is home to an estimated 3,601 residents, and 1,181 households.