Svalbard Airport (Norwegian: Svalbard lufthavn; IATA: LYR, ICAO: ENSB) is the main airport serving Svalbard in Norway. It is 5 km (3.1 mi) northwest of Longyearbyen on the west coast, and is the northernmost airport in the world with scheduled public flights. The first airport near Longyearbyen was constructed during World War II. In 1959, it was first used for occasional flights, but could only be used a few months a year. Construction of the new airport at Hotellneset started in 1973, and the airport was opened on 2 September 1975. It is owned and operated by state-owned Avinor.

In 2014, the airport handled 154,261 passengers. Scandinavian Airlines operates daily flights to Tromsø and Oslo in mainland Norway. Lufttransport provides services to the other airport on Svalbard: Ny-Ålesund, using Dornier 228 turboprop aircraft. There are also regular charter flights.

The first airstrip on Svalbard was constructed in Adventdalen, near Longyearbyen, by the Luftwaffe during World War II. It was not used immediately after the war; during the summer the archipelago was served by ships but was completely isolated from November to May. In the early 1950s, the Norwegian Air Force started postal flights using a Catalina aircraft that departed from Tromsø and dropped postal parcels at Bear Island and at Longyearbyen. However, these aircraft never landed until 9 February 1959, when a resident had become seriously ill and needed to be flown to mainland Norway for treatment. The mining company Store Norske Spitsbergen Kulkompani cleared the runway at Adventsdalen and the 14-hour flight and landing were successful. A second landing, this time for delivery of post, was made on 11 March.

While the Catalina was suitable for postal flights, it was not suitable as a permanent solution for transporting passengers and freight, mainly due to its small size. Store Norske contacted the domestic airline Braathens SAFE for a regular service. A Douglas DC-4 flew the first trial flight on 2 April 1959, with 54 passengers from Bardufoss Airport. Store Norske had cleared a 1,800 by 40 metres (5,910 by 130 ft) runway for the aircraft. The next flight occurred in 1962, followed by another in 1963 and two in 1964.^{[citation needed]}

The absence of runway lights meant that flights were only permitted during daylight. This hindered flights during parts of December and January when the sun never rises. By April, the runway ice would begin melting as the sun would appear allowing flights during the summer. Navigation was conducted using radio signals from Bear Island and Isfjord.

The first night landing was made on 8 December 1965. A DC-4 took off from the new Tromsø Airport and delivered the mail at Bear Island before continuing to Longyearbyen. The runway was lit up using paraffin lamps and lights from cars parked along the runway. A radio transmitter was also installed at Hotellneset. During the 1965–66 season, Braathens SAFE made 16 flights to Svalbard. The following two seasons, a contract was awarded to Scandinavian Airlines System (SAS), but after that, the contract reverted to Braathens SAFE. Fred. Olsen Airtransport made its first flight to Svalbard in 1966. By 1969, a total of 50 flights had been made to Svalbard, and by 1972, the 100th was made. By then, Braathens SAFE had started using Douglas DC-6B aircraft. During these years, Store Norske also installed permanent lights. The first jet plane to land in Adventdalen was a Fred Olsen Flyselskap Dassault Falcon 20, LN-FOI. The landing was in 1971, and the aircraft brought in 1700 lbs of mail and passengers, picking up a geological survey party. A Fokker F-28 landed on 29 April 1972. From 1974, Boeing 737-200C aircraft were taken into use. They had a side cargo door, allowing easy loading of cargo into the main cabin. Braathens SAFE built a small depot with spare parts and up to 90,000 litres (20,000 imp gal; 24,000 US gal) of fuel. Aeroflot started flights to Adventdalen in 1973 to serve the neighboring Russian community of Barentsburg.

The Svalbard Treaty specifies that no military installations are permitted on the archipelago. The Soviet authorities were concerned that a permanent civilian airport could also be used by Norwegian and NATO forces. But the Soviets also needed an airport to serve their settlements at Barentsburg and Pyramiden, and by the early 1970s, an understanding was reached between the two countries.

Construction started in 1973. The airport needed to be built on permafrost. The runway is insulated against the ground, so it will not melt during the summer. The hangar is frozen into the ground, with the pillars being melted into place and then being frozen stuck. The runway was plagued with frost heaves due to an incorrect construction method, forcing the airport to regularly re-asphalt the runway. In 1989, parts of the runway were re-insulated, repairing those areas that previously had been the worst of an acceptable solution. In 2006, this solution was administered to the remaining parts of the runway. An upgrade to the terminal building to allow larger capacity was completed in 2007. The runway was renumbered from 10/28 to 09/27 on 07 September 2023.