Mill Island is a residential neighborhood in the southeastern part of Brooklyn. It is located on a peninsula abutting Jamaica Bay and is bordered by Avenue U on the north and the Mill Basin inlet on its remaining sides. It is adjacent to the neighborhood of Bergen Beach to the northeast, Flatlands to the northwest, Marine Park to the southwest, and Floyd Bennett Field to the southeast. Mill Basin also contains a subsection called Old Mill Basin, north of Avenue U and south of Avenue N.
Mill Basin was originally known as Mill Island, located in Jamaica Bay. It has evolved into two (2) separate communities through the last several decades. To develop Mill Basin as a seaport district, ports and dry docks were built in the early 20th century. A lack of railroad connections hindered the area's further commercial growth. Residential development began in the 1950s, along with much of the rest of southeast Brooklyn, though some of the former industrial buildings remain.
The Mill Island portion of Mill Basin, bordering on Jamaica Bay, saw its development in the 1960’s into detached and semi-detached one and two-family homes, many of which have been categorized as some of the most luxurious homes in the borough. The western part of the neighborhood contains local strip shopping, commercial and industrial use. In the late 1960’s, the corner of Flatbush Avenue and Avenue U saw the development of Brooklyn first regional enclosed mall – The Kings Plaza Shopping Center and Marina.
Nearby recreational areas include Floyd Bennett Field, the first municipal airport in New York City, which is part of the Gateway National Recreation Area and is located just southeast of Mill Basin.