The Main Line is a rail line owned and operated by the Long Island Rail Road in the U.S. state of New York. It begins as a two-track line at Long Island City station in Long Island City, Queens, and runs along the middle of Long Island about 95 miles (153 km) to Greenport station in Greenport, Suffolk County. At Harold Interlocking approximately one mile east of Long Island City, the tracks from the East River Tunnels and 63rd Street Tunnel into Manhattan intersect with the Main Line, which most trains use rather than using the Long Island City station.

The Long Island City station is a rail terminal of the Long Island Rail Road in the Hunters Point and Long Island City neighborhoods of Queens, New York City. Located within the City Terminal Zone at Borden Avenue and Second Street, it is the westernmost LIRR station in Queens and the end of both the Main Line and Montauk Branch. The station consists of one passenger platform located at ground level and is wheelchair accessible.