Grand Central Terminal is a commuter rail terminal located at 42nd Street and Park Avenue in Midtown Manhattan, New York City. Grand Central is the southern terminus of the Metro-North Railroad's Harlem, Hudson and New Haven Lines, serving the northern parts of the New York metropolitan area. It also contains a connection to the Long Island Rail Road through the Grand Central Madison station, a 16-acre (65,000 m2) rail terminal underneath the Metro-North station, built from 2007 to 2023. The terminal also connects to the New York City Subway at Grand Central–42nd Street station. The terminal is the third-busiest train station in North America, after New York Penn Station and Toronto Union Station.

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.