Franklin is a borough in Sussex County, in the U.S. state of New Jersey. As of the 2020 United States census, the borough's population was 4,912, a decrease of 133 (−2.6%) from the 2010 census count of 5,045, which in turn reflected a decline of 115 (−2.2%) from the 5,160 counted in the 2000 census.

The Horsehead Holding Corporation, formerly The New Jersey Zinc Company, was an American producer of zinc and related materials based in Pittsburgh. The operations of the historic company are currently conducted as American Zinc Recycling.