Is Long Island really an island?

Montauk Point Lighthouse overlooks the Atlantic Ocean from the easternmost tip of Long Island, where rugged bluffs meet the sea. First commissioned by President George Washington in 1792 and placed into service in 1796, the historic lighthouse remains New York State's oldest and continues to serve as one of Long Island's most iconic landmarks and enduring symbols of the East End. — Montauk Point Lighthouse overlooks the Atlantic Ocean from the easternmost tip of Long Island, where rugged bluffs meet the sea. First commissioned by President George Washington in 1792 and placed into service in 1796, the historic lighthouse remains New York State’s oldest and continues to serve as one of Long Island’s most iconic landmarks and enduring symbols of the East End. File photo: Haveseen, licensed.

Long Island is, in fact, a true island. It is completely surrounded by water, with New York Harbor and the East River to the west, Long Island Sound to the north, the Atlantic Ocean to the south, and Block Island Sound and the Atlantic Ocean near its eastern end. Although many people associate Long Island with its suburban communities rather than an island, it is geographically one of the world’s largest islands.

In Short

Yes. Long Island is a genuine island because it is entirely surrounded by water. It stretches approximately 118 miles from west to east and is bordered by Long Island Sound, the Atlantic Ocean, New York Harbor, the East River, and Block Island Sound.

Is Long Island Really an Island?

Despite the common misconception, Long Island is unquestionably an island by every geographic definition. An island is a piece of land completely surrounded by water, and Long Island meets that definition. It is separated from mainland New York State by waterways including the East River, New York Harbor, and the tidal channels connecting to Long Island Sound.

To the north, Long Island is bordered by Long Island Sound, which separates it from Connecticut. To the south lies the Atlantic Ocean, while the island’s eastern end reaches Block Island Sound near Montauk and Orient Point. These surrounding waters completely isolate the island from the mainland.

One reason many people question whether Long Island is truly an island is that it is connected to the mainland by numerous bridges and tunnels, including those leading into New York City. However, man-made connections do not change its geography. Just as bridges connect islands around the world without changing their status, the bridges and tunnels serving Long Island simply provide transportation across the surrounding waterways.

Today, Long Island is home to nearly eight million residents living in Brooklyn, Queens, Nassau County, and Suffolk County, making it the most populous island in the contiguous United States.

Quick Facts

Category	Information
Is Long Island an island?	Yes. Long Island is completely surrounded by water.
North	Long Island Sound
South	Atlantic Ocean
West	New York Harbor and the East River
East	Block Island Sound, the Atlantic Ocean, Montauk, and Orient Point
Length	Approximately 118 miles (190 km)
Population	Nearly 8 million residents

Although its size, population, and extensive network of bridges and tunnels sometimes cause people to think of it as part of the mainland, Long Island is, by every geographic standard, a true island. Surrounded by the Atlantic Ocean, Long Island Sound, New York Harbor, the East River, and Block Island Sound, it remains one of the largest, most populated, and most recognizable islands in the United States.