The Hudson Line is a commuter rail line owned and operated by the Metro-North Railroad in the U.S. state of New York. It runs north from New York City along the east shore of the Hudson River, terminating at Poughkeepsie. The line was originally the Hudson River Railroad, and eventually became the Hudson Division of the New York Central Railroad. It runs along what was the far southern leg of the Central's famed "Water Level Route" to Chicago.

Metro-North Railroad, trading as MTA Metro-North Railroad, is a suburban commuter rail service operated by the Metropolitan Transportation Authority (MTA), a public authority of the U.S. state of New York. Metro-North serves the New York Metropolitan Area, running service between New York City and its northern suburbs in New York and Connecticut, including Port Jervis, Spring Valley, Poughkeepsie, Yonkers, New Rochelle, Mount Vernon, White Plains, Southeast and Wassaic in New York and Stamford, New Canaan, Danbury, Bridgeport, Waterbury, and New Haven in Connecticut. Service in Connecticut is operated under contract with the Connecticut Department of Transportation. Metro-North also provides local rail service within the New York City boroughs of Manhattan and the Bronx.