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.

The Outer Barrier, also known as the Long Island and New York City barrier islands, refers to the string of barrier islands that divide the lagoons south of Long Island, New York from the Atlantic Ocean. These islands include Long Beach Barrier Island, Barnum Island, Jones Beach Island, Fire Island and Westhampton Island. The outer barrier extends 75 miles (121 km) along the South Shore of Long Island, from the Rockaway Peninsula in New York City to the east end of Shinnecock Bay in Suffolk County.