Long Beach Island is a barrier island and summer colony along the Atlantic Ocean coast of Ocean County, New Jersey, United States, on the Jersey Shore. Aligned north to south, the northern portion generally has more expensive low-density housing, whereas the southern portion possesses higher-density housing and considerable commercial development. Long Beach Island is 1-2 miles away from Mainland New Jersey. The primary industries include tourism, fishing, and real estate. The only access point to the island by land is a single causeway. The island is the southernmost point of the New York Metropolitan Area.

Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers, with islands periodically separated by tidal inlets. The largest barrier island in the world is Padre Island of Texas, United States, at 113 miles (182 km) long. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula, often including a beach, barrier beach. Though many are long and narrow, the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.