Bergen Beach is a residential neighborhood in the borough of Brooklyn, New York City. It is located on a peninsula abutting Jamaica Bay in the southeastern portion of the borough, and is bordered by Mill Basin and the neighborhood of the same name to the south and west; the neighborhood of Flatlands to the northwest; Paerdegat Basin and the neighborhood of Canarsie to the northeast; and Jamaica Bay and the Belt Parkway to the east. Bergen Beach contains a sub-neighborhood named Georgetown. The vast majority of residents are white, and the neighborhood generally has a suburban quality.

Bergen Beach was originally an island. The Canarsie Indians who occupied the area referred to it as Winnipague. The island was renamed Bergen Island for early settler Hans Hansen Bergen. From 1896 to 1919, Percy G. Williams and Thomas Adams operated an amusement park in the area. Bergen Beach was connected to the rest of Brooklyn via landfill by 1918, although development did not come for many years. In the 1960s, a housing development called "Georgetowne" was proposed for Bergen Beach, but it was never built due to opposition from local residents. As a result, much of Bergen Beach was not fully developed until the 1990s.

Bergen Beach is part of Brooklyn Community District 18, and its primary ZIP Code is 11234. It is patrolled by the 63rd Precinct of the New York City Police Department.

Originally, Bergen Beach was an island in Jamaica Bay off the coast of Canarsie, called "Bergen Island" or "Bergen's Island". Most of the island was sea-level meadows, but 60 acres (24 ha) of the island were uplands, or hilly areas located above sea level. The sea-level meadows were replete with shell middens, or mounds, harvested from univalves and bivalves caught in Jamaica Bay. A bulkhead was built along the shore in the late 1890s, and was later connected to the uplands of nearby Mill Basin. This created a continuous embankment between Mill Basin and Paerdegat Basin, which was later used for the construction of Belt Parkway.

Bergen Island was connected to the mainland by 1918, when the marshland was filled in, though some sources state that the island was connected to the mainland by 1911. More fill was added in the 1980s. This fill was unstable, and as a result, parts of Bergen Beach have been sinking. Many homes in the area were built so that if the ground in front of the house sank, extra steps could be added. The sinking land is particularly pronounced in some parts of Bergen Beach, where minor rainfall or snow melt can cause ponding and flooding in the streets.

The modern neighborhood of Bergen Beach is adjacent to Canarsie and Paerdegat Basin to the northeast, Flatlands to the west, Mill Basin to the southwest, and Jamaica Bay to the southeast. The website Forgotten NY delineates the boundaries of Bergen Beach as Paerdegat Basin to the northeast, Ralph and Mill Avenues to the west, Avenue U and the Little Mill Basin waterway to the southwest, and Jamaica Bay to the southeast. Google Maps defines the boundaries similarly, except that Veterans Avenue, instead of Avenue U, forms part of the southwestern boundary. Georgetown is considered a subsection of Bergen Beach. It is bounded by Ralph Avenue to the west, Avenue N to the south, Avenue U to the southeast, and Paerdegat Basin to the northeast. Both Bergen Beach and Georgetown are zoned as predominantly residential neighborhoods with one- or two-family residences. Small commercial overlays and recreational waterfront uses also exist, and a strip along Bergen Basin is zoned for light industrial uses.

The coastal lands around Jamaica Bay, including present-day Bergen Beach, were originally settled by the Canarsie Indians. At the time, the Native Americans referred to Bergen Island as "Winnipague" or "Winnippague". The Canarsie Indians also called the island "Wimbaco", a name meaning "fine water place". The Native Americans likely used Bergen Island to create wampum. This location may have been chosen because it was easy to defend: the Indians could see intruders from the uplands and form a line of defense across the narrow flat that led to the island. Through the 20th century, the shell middens that resulted from the wampum-making process were used to create roads, as well as for fertilizer. Remnants of Native American activity on the island, including stone markings, conch shell beds, and broken arrow tips, could be seen through the mid-20th century. Bergen Island may also have contained fields that the Indians used for planting. There were collectively three planting fields on Bergen Island and in Canarsie.

In 1624, the Dutch Republic incorporated much of the current New York City area into the colony of New Netherland. In 1636, as the Dutch were expanding outward from present-day Manhattan, Dutch settlers founded the town of Achtervelt (later Amersfoort) and purchased 15,000 acres (6,100 ha) around Jamaica Bay. Amersfoort was centered around the present-day intersection of Flatbush Avenue and Flatlands Avenue. The Dutch also founded a trading post on Bergen Island, which they renamed "Mentelaer's Island". Ownership of Bergen Island was granted to John Underhill in 1646, and Underhill soon sold the property to others. New Netherland became British New York in 1664, and Amersfoort was renamed Flatlands. Bergen Island, as well as nearby Mill Island and Barren Island, were part of the Town of Flatlands. A settler named Elbert Elbertse bought Bergen Island in 1665, and by the 1670s, all three islands were leased by Elbertse. When he died in 1686, he bequeathed 60 acres (24 ha) of the island to his son.