Sunset Park is a neighborhood in the western part of the New York City borough of Brooklyn, bounded by Park Slope and Green-Wood Cemetery to the north, Borough Park to the east, Bay Ridge to the south, and New York Harbor to the west. The neighborhood is named for a public park of the same name that covers 24.5 acres (9.9 ha) between Fifth and Seventh Avenues from 41st to 44th Street. The area north of 36th Street is alternatively known as Greenwood Heights, while the section north of 24th Street is also called South Slope.

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.