The United Nations Headquarters is a distinctive complex in New York City that has served as the headquarters of the United Nations since its completion in 1950. It is located in the Turtle Bay neighborhood, on the east side of Midtown Manhattan, on spacious grounds overlooking the East River. Though it is in New York City, the land occupied by the United Nations Headquarters is considered "international territory", and its borders are First Avenue west, East 42nd Street south, East 48th Street north and the East River east. FDR Drive passes underneath the Conference Building of the complex.

The United Nations Headquarters were constructed in New York City in 1949 and 1950 beside the East River, on seventeen acres of land purchased from the foremost New York real estate developer of the time, William Zeckendorf. This purchase was arranged by Nelson Rockefeller, after an initial offer of placing it on the Rockefeller family estate of Kykuit was rejected as being too isolated from Manhattan. The $8.5 million purchase was then funded by his father, John D. Rockefeller, Jr., who donated it to the City. The lead architect for the building was the real estate firm of Wallace Harrison, the personal architectural adviser for the family.