The United Nations General Assembly Building is part of the headquarters of the United Nations in the Turtle Bay neighborhood of Manhattan in New York City. It contains the main assembly hall of the United Nations General Assembly, the main deliberative, policymaking, and representative organ of the United Nations (UN). The building was designed by a group of architects led by Wallace Harrison. It is connected to the other buildings in the UN headquarters, including the Secretariat Building and the Dag Hammarskjöld Library. Although the building is physically within the United States, it is exempt from some local regulations because the site is under UN jurisdiction.

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.