Map - O. R. Tambo International Airport (O.R. Tambo International Airport)

O. R. Tambo International Airport is an international airport serving the twin cities of Johannesburg and the main capital of South Africa, Pretoria. It is situated in Kempton Park, Gauteng. It serves as the primary airport for domestic and international travel for South Africa and since 2020, it is Africa's second busiest airport, with a capacity to handle up to 28 million passengers annually. The airport serves as the hub for South African Airways. The airport handled over 21 million passengers in 2017.

It was originally known as Jan Smuts International Airport, after the former South African Prime Minister of the same name. The airport was renamed Johannesburg International Airport in 1994 when the newly elected African National Congress (ANC) government implemented a policy of not naming airports after politicians. This policy was later reversed, and on 27 October 2006 the airport was renamed after anti-apartheid politician Oliver Reginald Tambo (1917–1993).

The airport was founded in 1952 as Jan Smuts International Airport, two years after Smuts's death, near the town of Kempton Park on the East Rand. It replaced Palmietfontein International Airport, which had handled European flights since 1945.

In 1943, a decision was made by the Cabinet of the Union of South Africa to construct three international airports with a Civil Airports Advisory Committee formed to investigate and report on the viability. That report was submitted to the Cabinet in March 1944 with one main international airport on the Witwatersrand and two smaller international airports at Cape Town and Durban. The South African Railways and Harbours Administration was given the role of managing the project and later in 1944, a member went to the United States to study standards and methods of construction. Four possible sites around Johannesburg were identified, with one south of Johannesburg chosen but soon discarded due to being situated on land with gold bearing reefs below. Sites were then narrowed down to Kempton Park and the existing airport at Palmietfontein.

Layouts and rough costing for the two sites were established and submitted for a ministerial decision. The site would be at Kempton Park and be named Jan Smuts Airport. The area outside Kempton Park was an expropriated undulating dairy farm of 3,706 acres with a 598 acre eucalyptus plantation. Sitting on a plateau, the area sloped away towards the east. The area was drained by the Blesbok River. The airport became operational on 1 September 1953. The new airport was officially opened by Minister for Transport, Paul Sauer on 4 October 1953 having taken eight years to build at £6.2 million. It had one main runway of 3,200m and two smaller ones of 2,514m that crossed the main with all runways being 60m wide. A 1,000 men had been employed in the repair workshops. The technical areas consisted of 2,957m of roads, 26,477sqm of concrete apron while the hangars had openings of 106m at a height of 21m. It was expecting to manage thirty flights-a-day and over 200,000 passengers that year. Airlines using the airport at its opening were BOAC, Air France, KLM, SAA, Central African Airways, Qantas, El Al, SAS Group and DETA.

In the late 1950s, jet passenger aircraft became the norm and there was a need to expand the existing ground facilities at the airport, which began in the 1960s and early-1970s. In addition to the new airside facilities, ground developments included: improved road access, parking areas, hotel, retail areas and car hire.

The late-1960s saw a new choice of aircraft for South African Airways, the Boeing 747. A decision was made by the Minister of Transport to obtain three, later five 747s for the airline. Delivery would begin in October 1971 with the first flight to London on 10 December 1971 with daily services from February 1972. These purchases however required new hangar facilities with the contract awarded in September 1969 initially worth R2,983,408. Construction started in December 1968 and was completed in October 1971 for R8,000,000 while other work at the airport associated with the arrival of these new aircraft brought the costs to R40,000,000. Other new buildings such as workshops, testing facilities, stores, staff accommodation and air cargo handling building were built. The new hangar would allow for two 747s in each bay with dimensions of 73.2 m wide, 24.4 m high and a depth of 91.4 m.

It was used as a test airport for Concorde during the 1970s, to determine how the aircraft would perform while taking off and landing at high elevations ('hot and high' testing). During the 1980s, many countries stopped trading with South Africa because of the United Nation sanctions imposed against South Africa in the struggle against apartheid, and many international airlines stopped flying to the airport. These sanctions also resulted in South African Airways being refused rights to fly over most African countries, and in addition, the risk of flying over some African countries was emphasised by the shooting down of two passenger aircraft over Rhodesia (e.g. Air Rhodesia Flight 825 and 827), forcing them to fly around the "bulge" of Africa. This required specially-modified aircraft like the long-range Boeing 747SP. A second runway was built at the airport in the late-1980s.

In December 1993, a R120,000,000 upgrade at the airport was completed. The main part of the projects was an 880 m, 3000 t steel airside corridor consisting of two levels high of 6 m wide with thirteen passenger bridges. The upper levels are connected the departure lounges through security screening points. Lower levels are for arrivals for entry into the immigration and custom areas. A future provision for extensions to this airside corridor was included in the design. A new airside bus terminal was also added for bussing in passengers to aircraft not able dock next to the terminal. Other parts of the project included upgrading the terminal facilities for the passengers.

Following the ending of apartheid, the airport's name, and that of other international airports in South Africa, were changed and these restrictions were lifted. With the creation of the Airports Company of South Africa (ACSA) in the mid-nineties, a plan to commercialise the airport began with new passenger and retail and airside facilities to handle a larger number of aircraft completing this phase in 2004.