The A340 was assembled in Toulouse, France. It seats up to 375 passengers in the standard variants and 440 in the stretched -600 series. Depending on the model, it has a range of 6,700 to 9,000 nautical miles (12,400 to 16,700 km; 7,700 to 10,400 mi). Its distinguishing features are four high-bypass turbofan engines and three-leg main landing gear.

The A340 was manufactured in four fuselage lengths. The initial variant, A340-300, which entered service in 1993, measured 63.69 metres (209.0 ft). The shorter -200 was developed next, and the A340-600 was a 15.96 metres (52.4 ft) stretch of the -200.

The -600 was developed alongside the shorter A340-500, which would become the longest-range commercial airliner until the arrival of the Boeing 777-200LR.

The initial A340-200 and -300 variants share the fuselage and wing of the twin-engine Airbus A330 with which it was concurrently designed. The heavier A340-500 and -600 are stretched and have enlarged wings.

Launch customers Lufthansa and Air France placed the A340 into service in March 1993. In September 2011, 379 orders had been placed (not including private operators), of which 375 were delivered. The most common type is the A340-300 model, with 218 aircraft delivered. Lufthansa, the biggest operator of the A340, acquired 62 aircraft, and continues to operate 32 -300 and -600 series variants as of June 2019. The A340 is used mainly on long-haul, trans-oceanic routes due to its immunity from ETOPS restrictions; however, with reliability and fuel efficiency in engines improving, airlines are gradually phaseing out the type in favour of more economical twinjets of comparable capacity such as the Boeing 777 while Airbus has positioned the larger variants of the Airbus A350 as a successor. Airbus announced on 10 November 2011 that A340 production had been concluded.

The aircraft with similar capabilities and configurations are: Boeing 777, and the new Airbus A350.