[3] The airport is located 19 nautical miles (35 km; 22 mi) northeast of Oslo, at Gardermoen at the border of municipalities Nannestad and Ullensaker, in Akershus county.

[9] During the occupation of Norway by Nazi Germany, the Luftwaffe took over Gardermoen, and built the first proper airport facilities with hangars and two crossing runways, both 2,000 metres (6,600 ft) long.

Some commercial traffic returned again in 1960, when SAS received its first Sud Aviation Caravelle jet aircraft, that could not use the runway at Fornebu until it was extended again in 1962.

In 1983, further restrictions were enforced, and also SAS and Braathens SAFE had to move their charter operations to Gardermoen, increasing passenger numbers that year to 750,000.

[13] Norway's first airline, Det Norske Luftfartrederi, was founded in 1918 and the first scheduled flights were operated by Deutsche Luft Hansa to Germany with the opening of Gressholmen.

But due to its location on a peninsula about 8 kilometres (5.0 mi) from the city center and close to large residential areas, it would not be possible to expand the airport sufficiently to meet all foreseeable demands in the future.

[19] During the 1970s, it became a political priority by the socialist and center parties to reduce state investments in Eastern Norway to stimulate growth in rural areas.

In 1994, Engineer Jan Fredrik Wiborg, who claimed that falsified weather reports had been made, died after falling from a hotel window in Copenhagen.

SAS built a complex with 55,000 square metres (590,000 sq ft), including a technical base, cabin storage, garages and cargo terminals, for NOK 1.398 billion.

This line was constructed for 210 kilometres per hour (130 mph) and allows the Flytoget train to operate from Oslo Central station to Gardermoen in nineteen minutes.

The low-cost airline took advantage of the increased capacity that Gardermoen created to start competing with SAS and Braathens on the routes to Bergen, Trondheim and Ålesund.

[26] The use of deicing fluids is restricted since the area underneath the airport contains the Tandrum Delta, one of the country's largest uncontained quaternary aquifers (underground water systems).

[41] In October 2001, the only remaining intercontinental flight, to Newark Airport (EWR), with Scandinavian Airlines (SAS) operated Boeing 767–300 aircraft, was discontinued, due to a slump in air travel following the 9/11 attacks.

In 2012, the airport opened a new 650-square-meter (7,000 sq ft) VIP terminal exclusively used for the royal family, the prime minister and foreign heads of state and government.

As a consequence of the delays, which apparently were caused by a lack of air traffic controllers, several airlines received NOK 100 million in compensation from Avinor.

[33] The airport's architects were Aviaplan, a joint venture between the agencies Nordic — Office of Architecture, Niels Torp, Skaarup & Jespersen and Hjellnes Cowi.

[69] The new pier is cladded with oak from Scandinavian rainforests, and features low-carbon technologies such as district heating and natural thermal energy to improve sustainability.

On the airside, Carin Wessel used 30,000 metres (98,000 ft) of thread to make the impression of clouds and webs, named Ad Astra.

Anna Karin Rynander and Per-Olof Sandberg cooperated in making two installations: The Marathon Dancers, located in the baggage claim area, is a set of two electronic boards that show a dancing person.

[70] At the National Road 35 and European Route E6 junction, Vebjørn Sand built a 14-metre (46 ft) statue named the Kepler Star.

[33] The runways are equipped with CAT IIIA instrument landing system[71] and the airport is supervised by a 91-metre (299 ft) tall control tower.

[61] Once departing aircraft are 15 kilometres (9 mi) away from the airport, responsibility is taken over by Oslo Air Traffic Control Center, which supervises the airspace with Haukåsen Radar.

When the coronavirus pandemic came to Norway in March 2020, Norwegian had to close down its long-haul fleets after a short time, because there was not a sufficient customer base.

As a result, the Norwegian Air Transport Authority, Avinor, approved plans on 19 January 2011, for an expansion of OSL with Terminal 2 (North Pier).

Finished in Spring 2017, the expansion involved construction of a new pier located directly after security checkpoint with eleven new air bridges, six remote stands, a new arrivals- and departure-hall and a new baggage handling system.

[190][52] Yet, before the North Pier was finished, OSL have invested further plans to expand the international terminal with six new wide-body airliner gates for more direct flights to destinations outside of Europe.

[194][195] If passenger traffic continues to grow and if the capacity will be surpassed beyond the capabilities, OSL and Avinor will call out for a master phase (as situated in the Master Plan 2012–2050), including extension of the North Pier by another 100 meters, adding a third runway with a free-standing pier between it and the existing Eastern runway, as well as a new terminal to the southeast area of the current international terminal (by where Park Inn is located).

However, as of December 2017, construction of a nearby city directly to the east of OSL has been officially approved, nicknamed "the Gate to Europe", in which a third runway and a third terminal are part of the project.

[198] Norwegian CEO Bjørn Kjos has announced that the airline has ambitions to evolve Gardermoen into a major global hub between North America and South Asia.

He guarantees the transatlantic routes will be significantly shorter via Northern Europe, which will lead to increased efficiency and satisfaction for the travelers and for the economy.