Canarsie is a mostly residential neighborhood in the southeastern portion of Brooklyn, New York City. Canarsie is bordered on the east by Fresh Creek Basin, East 108th Street, and Louisiana Avenue; on the north by Linden Boulevard; on the west by Ralph Avenue; on the southwest by Paerdegat Basin; and on the south by Jamaica Bay. It is adjacent to the neighborhoods of East Flatbush to the west, Flatlands and Bergen Beach to the southwest, Starrett City to the east, East New York to the northeast, and Brownsville to the north.

Brooklyn is a borough of New York City. Located on the westernmost end of Long Island, it is coextensive with Kings County in the U.S. state of New York. With 2,736,074 residents as of the 2020 United States census, Kings County is the most populous of the five boroughs of New York City and the most populous county in the State of New York. The population density of Brooklyn was 37,339.9 inhabitants per square mile (14,417.0/km2) in 2022, making it the second-most-densely-populated county in the United States, behind Manhattan, and it had the ninth-highest population of any county nationwide. Were Brooklyn still an independent city, it would be the fourth most populous in the U.S. after the rest of New York City, Los Angeles, and Chicago.