The Long Beach Branch is an electrified rail line and service owned and operated by the Long Island Rail Road in the U.S. state of New York. The branch begins at Valley Interlocking, just east of Valley Stream station, where it merges with the Far Rockaway Branch to continue west as the Atlantic Branch. East from there the Long Beach Branch parallels the Montauk Branch to Lynbrook station, where it turns south toward Long Beach station. Trains operating on the Long Beach Branch continue west of Valley Stream via the Atlantic Branch to Jamaica station, with most continuing on to Grand Central or Penn Station in Midtown Manhattan. In 2018, the branch recorded an annual ridership of 4,849,085 based on ticket sales, down 1% from 2017.

Long Beach is an oceanfront city in Nassau County, New York, United States. It takes up a central section of the Long Beach Barrier Island, which is the westernmost of the outer barrier islands off Long Island's South Shore. As of the 2020 Census, the city's population was 35,029.