Shannon has had a long association with transatlantic flight, owing to its position on the west coast of Ireland and being the most westerly international airport in Europe.

At 3.2 kilometres (2 mi), Shannon has the longest runway in Ireland, which allowed it to be a designated alternative landing site for the Space Shuttle.

In 1936, the Government of Ireland confirmed that it would develop a 3.1-square-kilometre (1.2 sq mi) site at Rineanna for the country's first transatlantic airport.

In July 1939, a SABENA Savoia-Marchetti S.73 from Brussels via Croydon Airport was the first commercial flight to use the Rineanna airfield.

BOAC began scheduled service to Bristol on 21 February 1942 to provide a land plane connection between England and the flying boat terminal at Foynes.

[10] By the end of World War II in 1945, the existing runways at Shannon were extended to allow transatlantic flights to take off.

[12] On 24 October 1945, the first scheduled transatlantic commercial flight using a land plane, an American Overseas Airlines DC-4, Flagship New England, stopped at the airport on the New York City–Gander–Shannon–London route.

[13] Trans World Airlines began service between New York and Paris via Gander and Shannon on 5 February 1946,[14] and began a Shannon-Dublin tag flight in 1971 after the US Civil Aeronautics Board threatened to ban Aer Lingus from landing in New York.

Aeroflot began service to Shannon in September 1975 as a stop between the Soviet Union and other Communist bloc countries, such as Cuba and Angola.

[18] Nonetheless, the Aeroflot operation returned and developed into a hub by the mid-1990s, with flights to New York, Chicago, Washington, Miami, and Havana, largely using Ilyushin Il-62 aircraft.

[19] The cooperation between Aeroflot and Aer Rianta at Shannon also led to a joint venture between the two companies to open duty-free shops at Sheremetyevo Airport in 1987.

[citation needed] However, after a disagreement with the Dublin Airport Authority (DAA) in 2008, Ryanair announced that the number of based aircraft would be reduced from four to one and 150 jobs would be lost.

[citation needed] CityJet launched a twice-daily route to Paris Charles de Gaulle Airport in 2008 when Aer Lingus closed its London Heathrow flights.

More services were under consideration, including a route to London City Airport; however CityJet pulled out of Shannon in October 2009 after Aer Lingus reinstated its Heathrow flights.

On 21 March 2013, Ryanair announced a new twice-weekly route to Alicante, Spain, to begin on 5 June for the summer months.

In August 2013, Aer Lingus announced a 1x weekly service to Lanzarote, Canary Islands, Spain, every Saturday during the winter months, using an A320.

[citation needed] In late 2013, Aer Lingus announced 2 new routes to Málaga, Spain, (two weekly) and to Bristol, UK, (one daily).

The new routes began from the start of April 2014, and a second Boeing 737-800 was based at Shannon to accommodate the extra 300,000 passengers a year it would bring in.

The destinations announced were Berlin Schonefeld, Beauvais, Memmingen, Warsaw Modlin, Kraków, Nice, Faro, and Fuerteventura.

The East Midlands, Bristol and Ibiza flights are all being ceased at the end of the 2019 summer season due to fears of Brexit and the 737 MAX groundings.

[citation needed] Due to the 737 MAX groundings, Air Canada and Norwegian Airlines suspended their routes to Shannon.

[23] On 23 October 2019, Lauda announced that they will launch a twice weekly flight to Shannon from their base in Vienna, operating every Wednesday and Saturday.

There were some restrictions, such as carrying no arms, ammunition, or explosives, and that the flights in question did not form part of military exercises or operations.

[29] On 6 December 2005, the BBC programme Newsnight alleged that Shannon was used on at least 33 occasions by United States Central Intelligence Agency (CIA) flights, thought to be part of a US policy called extraordinary rendition.

[30] German Khaled El-Masri, who was mistakenly tortured by the CIA after being abducted by the Macedonian police, was taken to an Afghan black site by a plane which had stopped at Shannon Airport on its way to North Macedonia to pick him up.

[37] In 2024, Aer Lingus announced the airline would be closing its Shannon based cargo facility citing low demand and lack of commercial justification to remain present there.

To have these facilities put in place, a two-storey, 7,000 m2 (75,000 sq ft) extension to the main terminal building was constructed.

[69] Private-hire coaches and buses such as Eirebus are available from many operators;[70] these need to be pre-booked and can transport passengers to any destination in Ireland.