The Northern Branch is a railroad line that runs from Jersey City to Northvale in northeastern New Jersey, and formerly extended further into New York State. The line was constructed in 1859 by the Northern Railroad of New Jersey to connect the New York and Erie Railroad's Piermont Branch terminus in Piermont, New York, directly to Erie's primary terminal in Jersey City, initially Exchange Place, later Pavonia Terminal. In 1870 the line was extended to Nyack, New York, and continued to provide passenger service until 1966. After the Erie's unsuccessful merger with the Lackawanna Railroad to form the Erie-Lackawanna, ownership of the line passed into the hands of Conrail upon its formation in 1976 from a number of bankrupt railroads (including the E-L).

The line survives as two separate but connected sections. The Northern Running Track is an approximately two-mile-long freight railroad line in Hudson County, New Jersey. It runs from the Passaic and Harsimus Line at Marion Junction in western Jersey City north to the North Bergen Yard and the CSX Transportation's River Subdivision. North of the rail yard the Northern Branch diverges from the River Subdivision and continues north to the New York state line as a minor spur.

The Northern Branch Corridor Project is a NJ Transit proposal to restore passenger service on the line as an extension of the Hudson–Bergen Light Rail from the current Tonnelle Avenue terminus in North Bergen to Englewood.