Gerritsen Beach is a neighborhood in the New York City borough of Brooklyn, located near Marine Park and Sheepshead Bay. The area is served by Brooklyn Community Board 15.

Gerritsen Beach lies on a peninsula in the southeastern part of Brooklyn, near Marine Park; it is bounded on the north by Avenue U, to the east by Gerritsen Avenue, to the south by the Plumb Beach Channel, and on the west by Shell Bank Creek and Knapp Street. It is bisected, from west to east, by the Gotham Avenue Canal. The area north of the canal, known as the "new section" by local residents, has traditional city streets lined with stores, brick houses, and wide sidewalks; the elementary school, P.S. 277 ("The Gerritsen Beach School"),is also north of the canal. The area south of the canal (the "old section") retains the character of a small fishing village and is a popular spot for party boats and chartered fishing boats to be berthed. The streets in Gerritsen Beach are in alphabetical order (that is, Aster, Bevy, Celeste, Dictum, etc.), and they are patrolled by officers of the New York Police Department's 61st Precinct.

The neighborhood is named for Wolphert Gerretse, a Dutch settler, who, in the early seventeenth century, built a house and mill on Gerritsen Creek (which is now part of Marine Park.). The three-hundred-year-old mill was destroyed by fire in 1931.

Until the early twentieth century, the area remained undeveloped except for a few squatters’ bungalows clustered at the foot of Gerritsen Avenue. In 1920, Realty Associates, a speculative real-estate builder, began constructing a middle-class summer resort there. The southwestern section of Gerritsen’s meadow was soon covered by one-story bungalows with peaked roofs and no backyards; typically, these houses were built on tiny 40-by-45-foot lots. The popularity of this venture spurred further growth. Some bungalow-owners made them suitable for year-round habitation; others built two-story houses with backyards; and, within a decade, there were fifteen hundred houses in Gerritsen Beach. With its narrow streets and closely-bunched homes (some sitting directly at the water's edge), this neighborhood in south Brooklyn is often likened to a New England fishing village.

The neighborhood has residents of many different races and ethnic backgrounds, but there is a large Irish-Catholic presence in the community. A few long-standing residents of Irish descent refer to the community as being cois farraige, which is a Gaelic phrase meaning "by the sea."

Resurrection Roman Catholic Elementary School operated until the end of the 2004-2005 school year when it was closed by the diocese. Currently, the Brooklyn Blue-Feather School for special-needs children operates in the former Resurrection school building. The neighborhood is also home of the New York City Department of Education's Public School 277 (P.S. 277), an elementary school known simply as "the Gerritsen Beach School."

The Gerritsen Ballfields, consisting of three baseball fields, two athletic fields for soccer or football, and one Little League field, are located on the east side of Gerritsen Avenue. In 1993, this site benefitted from a $192,000 renovation sponsored by Borough Council Member Herbert E. Berman. The park area also supports a "mini-airport" for motorized model airplanes; it is located at Seba Avenue and Gerritsen Avenue.

Recreational fishing is very popular with citizens of the community. Anglers can be found fishing along the shore at the southern end of Gerritsen Avenue and along the adjacent shoreline of the Gerritsen Creek-Marine Park 'salt marsh'. The Gerritsen Creek estuary and the adjacent salt marsh is also a major spawning ground for various species of marine fish.

The community is serviced by the New York City Transit bus B31, and the BM4 express bus.

Resurrection Roman Catholic Church, and St. James Evangelical Lutheran Church both serve the community.

The Gerrittsen Beach Volunteer Fire Department (a.k.a. "the Vollies"), the last remaining volunteer fire department in Brooklyn, was organized in 1922 when Gerrittsen Beach was a small summer-resort community. In 1921, a damaging fire on Abbey Court demonstrated to the community that the city’s regular fire apparatus could not reach the beach in time to put out a fire. A mass meeting was called by the residents, and that resulted in the organization of the only volunteer fire department in Brooklyn.

Before the city added water mains under Gerrittsen Beach streets, the Volunteers had to handle fires at least three times a week. The danger posed to Gerritsen Beach residents by fire was especially acute because most families relied on oil stoves and kerosene lamps, and the water to fight fires had to be pumped from wells. The city did not build Engine Company 321’s firehouse at Gerritsen Avenue and Avenue U until October 4, 1930.

Members of the fire brigade, currently known as the Vollies, were, in earlier times, nicknamed "the Vamps." Members are not only trained to fight fires, but also to rescue people who are drowning and to assist in other medical emergencies. According to the Vollies 1976 anniversary booklet, the Vollies were approved by the New York State Department of Health as an Emergency Services Training Center.

Even though the community is now served by Engine Company 321, strong support for the volunteer firemen housed at 52 Seba Avenue continues.

The following historical events involved the Gerritsen Beach volunteers in actions outside their own neighborhood:

The Gerritsen Beach Volunteer Fire Department has one fire engine, one ambulance, and one rescue vehicle. For further information, see Vollies.

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