The Salem Branch is a rail freight line in the southwestern part of New Jersey in the United States between the Port of Salem and Woodbury Junction where it and the Penns Grove Secondary converge with the Vineland Secondary, approximately 8.5 miles (13.7 km) south of Pavonia Yard in Camden.

The 11.5-mile (18.5 km) northern section is part of Conrail's Delaware Valley South Jersey/Philadelphia Shared Assets Operations and known as the Salem Running Track; it is leased to the Southern Railroad of New Jersey (reporting mark SRNJ).

The 18.6-mile (29.9 km) southern portion is owned by Salem County and operated under contract by SMS Rail Lines (reporting mark SLRS).

The PRR bought two-thirds of RDG's stock, and the consolidation, Pennsylvania-Reading Seashore Lines (PRSL), became effective June 25, 1933.

The southern 17.4 miles (28.0 km) of the line and the 1.2-mile (1.9 km) Glass House Spur to the Port of Salem was sold by Conrail to Salem County in 1985,[8] which in 1988 leased the line to Pioneer Railcorp subsidiary West Jersey Rail Company in 1988 to operate.

[24] In 2011, the South Jersey Port Corporation, Conrail, and Salem County received $18.5 million in federal money to partially fund rail infrastructure improvements for the 18-mile (29 km) Salem County Branch Line and a new link from the Penns Grove Secondary to Port of Paulsboro, and retrofitting of the Delair Bridge, the most downstream rail crossing of the Delaware River and crucial link between the national rail network and ports at Salem, Paulsboro and Camden.

[22][25] Prior to 2013, NJDOT had deemed various project work along the Salem Branch eligible for future state funding.

[30][31] In November 2017, a project to improve rail access at the end of the line in the Port of Salem was begun.