Lever House is a 307-foot-tall (94 m) office building at 390 Park Avenue in the Midtown Manhattan neighborhood of New York City. Constructed from 1950 to 1952, the building was designed by Gordon Bunshaft and Natalie de Blois of Skidmore, Owings & Merrill (SOM) in the International Style, a 20th-century modern architectural style. It was originally the headquarters of soap company Lever Brothers, a subsidiary of Unilever. Lever House was the second skyscraper in New York City with a glass curtain wall, after the United Nations Secretariat Building.

The International Style or internationalism is a major architectural style that was developed in the 1920s and 1930s and was closely related to modernism and modernist architecture. It was first defined by Museum of Modern Art curators Henry-Russell Hitchcock and Philip Johnson in 1932, based on works of architecture from the 1920s. The terms rationalist architecture and modern movement are often used interchangeably with International Style, although the former is mostly used in the English-speaking world to specifically refer to the Italian rationalism, or even the International Style that developed in Europe as a whole.