The Airbus A330 is a wide-body aircraft developed and produced by Airbus. Airbus began developing larger A300 derivatives in the mid-1970s, giving rise to the A330 twinjet as well as the Airbus A340 quadjet, and launched both designs along with their first orders in June 1987. The A330-300, the first variant, took its maiden flight in November 1992 and entered service with Air Inter in January 1994. The A330-200, a shortened longer-range variant, followed in 1998 with Canada 3000 as the launch operator.
The A330 shares many underpinnings with the airframe of the early A340 variants, most notably the same wing components, and by extension the same structure. However, the A330 has two main landing gear legs instead of three, lower weights, and slightly different fuselage lengths. Both airliners have fly-by-wire controls as well as a similar glass cockpit to increase the commonality. The A330 was Airbus's first airliner to offer a choice of three engines: the General Electric CF6, Pratt & Whitney PW4000, or the Rolls-Royce Trent 700. The A330-300 has a range of 11,750 km (6,340 nmi; 7,300 mi) with 277 passengers, while the shorter A330-200 can cover 13,450 km (7,260 nmi; 8,360 mi) with 247 passengers. Other variants include the A330-200F dedicated freighter, the A330 MRTT military tanker, and the ACJ330 corporate jet. The A330 MRTT was proposed as the EADS/Northrop Grumman KC-45 for the US Air Force's KC-X competition, but lost to the Boeing KC-46 in appeal after an initial win.

In July 2014, Airbus announced the re-engined A330neo (new engine option) comprising A330-800 and -900, which entered service with TAP Air Portugal in December 2018. With the exclusive, more efficient Trent 7000 turbofan and improvements including sharklets, it offers up to 14% better fuel economy per seat. The first-generation A330s (-200, -200F, and -300) are now called A330ceo (current engine option).

Delta Air Lines is the largest operator with 73 airplanes in its fleet as of November 2024. A total of 1,853 orders have been placed for the A330 family, of which 1,623 have been delivered and 1,473 are in service with 149 operators. The global A330 fleet had accumulated more than 65 million flight hours since its entry into service. The A330 is the second most delivered wide-body airliner after the Boeing 777. It competes with the Boeing 767, smaller variants of the Boeing 777, and the 787. It is complemented by the larger Airbus A350, which succeeded the four-engined A340. As of June 2024, the Airbus A330 has been involved in 46 aviation accidents and incidents, including 14 hull-losses (10 due to flight related accidents and 4 due to criminal related accidents), for a total of 339 fatalities.[2][3]