Completed in 1935, the 41-story, 512 ft (156 m) building was designed in the Art Deco style by Raymond Hood, Rockefeller Center's lead architect.

The main tower is set back from Fifth Avenue and includes two 6-story wings to the east, known as Palazzo d'Italia and International Building North.

[15] The International Building was designed by the Associated Architects of Rockefeller Center, composed of the firms of Corbett, Harrison & MacMurray; Hood, Godley & Fouilhoux; and Reinhard & Hofmeister.

[22][23] Hartley Burr Alexander, a mythology and symbology professor who oversaw Rockefeller Center's art program, led the installation of artwork throughout the complex.

The main tower was recessed as far back from Fifth Avenue as possible to maximize rental space while still complying with the 1916 Zoning Resolution,[28][23] which mandated that buildings contain setbacks above a certain height.

The gardens are also decorated with terracotta planters, two stone plaques transported from the Roman Forum, and walkways with cobblestones from Italian roads.

[41] Lee Lawrie's 15 ft-tall (4.6 m), 14,000 lb (6,400 kg) bronze Atlas statue is at the center of the Fifth Avenue entrance plaza, placed on a 9 ft-high (2.7 m) pedestal.

[30][20] When the building was developed, the Associated Architects gave the recessed main tower a one-story-tall entryway on Fifth Avenue, emphasizing the wings on either side.

The south face of the pier depicts Columbia (symbolizing America), greeting an immigrant woman who has just alighted from a ship, with the Manhattan skyline in the background.

[81][76] The lowest panel in the center bay contains four men, each signifying a different race;[83][82] the figures have the same skin color and are identified by their sculptural features.

[83][82][85] These are flanked by panels depicting "man's four habitats": a mosque (the East), an Aztec temple (the West), palm trees (the South), and a seagull and whale fluke (the North).

[30] For the 10 West 51st Street entrance (leading to International Building North), Lawrie designed a bas-relief with a woman and horn as an allegory for world cooperation.

[17] The project ultimately gained the support of John D. Rockefeller Jr.[17][114] The planned opera house was canceled in December 1929 due to various issues,[115][116][117] and Rockefeller quickly negotiated with Radio Corporation of America (RCA) and its subsidiaries, National Broadcasting Company (NBC) and Radio-Keith-Orpheum (RKO), to build a mass media entertainment complex on the site.

[125][19][126] Rockefeller Center's managers held talks with prospective Czech, German, Italian, and Swedish lessees who could potentially occupy the six-story internationally themed buildings on Fifth Avenue.

[124][134] The final plans did not arise until after the British and French buildings were completed, when the architects decided that a series of identical retail structures on Fifth Avenue would be esthetically pleasing.

The southern wing had been named the Italian Building (later the Palazzo d'Italia), and Italy's dictator Benito Mussolini had expressed his approval of the project.

By early July, Rockefeller Center's developers had leased 40,000 sq ft (3,700 m2) of space in the Palazzo, representing about a third of that structure's total floor area.

[143] The final small wing would have been rented by Germany under the name "Deutsches Haus", but Rockefeller ruled this out following Adolf Hitler's rise to power in 1932.

[21][48] The low accident rate was attributed to construction contractors' use of modern safety measures, as well as the use of automatic equipment and two staging areas for columns and beams on the building's seventh floor.

[154] In April 1935, Nelson Rockefeller hosted a ceremony in the International Building's lobby, giving craftsmanship awards to 31 workers who were involved in the project.

[180] Though the U.S. government forced the closure of the Italian consulate that June, Rockefeller Center officials initially indicated they would not rename the Palazzo.

[181] With the United States' entry into World War II that December, the Japanese consulate at the building was closed[182] and Piccirilli's artwork on the Palazzo wing boarded up, as the U.S. was fighting both Japan and Italy.

[184][189] When Sinclair Oil built a new headquarters two blocks south at 600 Fifth Avenue in the early 1950s, it vacated seven stories of space, which were quickly taken by Simon & Schuster and Esso.

[205] Manship's 6 ft-tall (1.8 m) statues, which had stood atop the Palazzo d'Italia since it opened, were removed in 1984 and relocated to Rockefeller Center's central plaza.

[222] During that decade, the International Building contained a business center shared by several small tenants, with reception and communications services as well as conference rooms.

[229][230] A preservation dispute arose in May 1998, when the owners announced plans to enlarge shop windows on the center's Fifth Avenue buildings to two stories.

[239] During the 2010s, office tenants included satellite television provider DirecTV, TV Guide Magazine, private equity advisory firm Campbell Lutyens,[238] and Rockefeller Capital Management.

The plans included cleaning wall and floor surfaces, adding recessed lighting, and creating brass niches beneath Ihara's lobby structures.

[96] Six years later, Goldberger said 30 Rockefeller Plaza's form, "made sumptuous by its mounting setbacks", contrasted with the "smaller and bulkier" International Building and other structures in the complex.

[247] Architect and writer Robert A. M. Stern wrote in his 1987 book New York 1930: "Its virtually reveal-less facades and detail-free columns and piers were complemented by the severe machine-like precision of the interior details.