The United Nations Secretariat Building is a skyscraper at the headquarters of the United Nations in the Turtle Bay neighborhood of Manhattan in New York City. It contains the offices of the United Nations Secretariat, the executive organ of the United Nations (UN). The building, designed in the International Style, is 505 ft (154 m) tall with 39 above-ground stories. It was designed by a group of architects led by Wallace Harrison. Although the building is located within the United States, the site is under UN jurisdiction, so the building is exempt from some local regulations.

The headquarters of the United Nations (UN) is on 17 to 18 acres of grounds in the Turtle Bay neighborhood of Midtown Manhattan in New York City. It borders First Avenue to the west, 42nd Street to the south, 48th Street to the north, and the East River to the east. Completed in 1952, the complex consists of several structures, including the Secretariat, Conference, and General Assembly buildings, and the Dag Hammarskjöld Library. The complex was designed by a board of architects led by Wallace Harrison and built by the architectural firm Harrison & Abramovitz, with final projects developed by Oscar Niemeyer and Le Corbusier. The term Turtle Bay is occasionally used as a metonym for the UN headquarters or for the United Nations as a whole.