Austrian Airlines (often shortened to Austrian or AUA) is the flag carrier of Austria and a subsidiary of Lufthansa, the flag carrier of Germany. The airline is headquartered on the grounds of Vienna International Airport in Schwechat, Austria, where it also maintains its hub. As of July 2016, the airline flew to six domestic and more than 120 international year-round and seasonal destinations in 55 countries and is a member of Star Alliance.

Air Austria and Austrian Airways merged to form the airline in 1957, but its history dates back to the founding of Austrian Airways in 1923. Throughout much of the company's existence, it was a state-owned entity. On 31 March 1958, the airline performed its scheduled service, flying a leased Vickers Viscount from Vienna to Zürich and London; it subsequently purchased its own Viscount fleet. On 18 February 1963, Austrian ordered its first jet-powered airliner, the Sud Aviation Caravelle. It subsequently introduced various models and derivatives of the Douglas DC-9 jetliner; by the end of 1971, Austrian was an all-jet operator. During the 1980s, it introduced the DC-9-80, otherwise known as the McDonnell Douglas MD-80, to its fleet. Various airliners produced by Airbus, Boeing, Fokker and other manufacturers were introduced across the 1980s and 1990s.

Throughout the 1990s, the airline sought out new strategic alliances, as well as to expand its presence in the long-haul market, launching new services to China and South Africa. In 2000, Austrian became a member of Star Alliance; a few years prior, it had also joined the Qualiflyer Group. During the 2000s, the airline expanded through the acquisitions of Rheintalflug and Lauda Air and adopted the shortened Austrian name in 2003. Throughout the 2000s, Austrian sustained several years of losses; during 2008, the airline's then-owner, the Austrian government, was advised to privatise Austrian via its sale to a foreign company. In 2009, the Lufthansa Group purchased Austrian after receiving approval from the European Commission following an investigation into the tendering process.

Following its privatisation, the business restructured, enacting both fleet expansion and cost-saving initiatives; visible changes included route alterations, a new corporate design, and a revised aircraft livery. Following labour disputes over several of the cost-cutting measures, all Austrian Airlines' flights were transferred on 1 July 2012 to its subsidiary, Tyrolean Airways, which operated under the Austrian name. A new labour agreement led to the transfer of all flights back to Austrian Airlines on 1 April 2015, and the merger of Tyrolean Airways into its parent company. During the late 2010s, restructuring of both its fleet and route network continued.

On 3 May 1923, Walter Barda-Bardenau received approval from the Austrian government to establish an airline. He participated in the newly formed Austrian Airlines (German: Österreichische Luftverkehrs AG) with one percent, with the remaining shares going to the Austrian railway transportation company (50%) and the Junkers-Werke (49%).

The company's initial fleet consisted of Junkers F 13s. On 14 May 1923, the first flight performed by the fledging airline was conducted between Vienna and Munich, piloted by Hans Baur. The landing occurred in Jedlesee, followed by a conversion to a float and a subsequent flight to Budapest. Junkers Trans European Union was the company operating the flight. Its destinations included Munich, Budapest, Nuremberg, Graz, Klagenfurt, and St. Wolfgang. Seaplanes served targets in Austria. September 1926 saw the dissolution of the union.^{[citation needed]}

From 1927, the company procured new aircraft with support from the government. During the same year, it formed an operating partnership agreement with Deutsche Luft Hansa. The two companies jointly planned and operated line connections and created a route network to Berlin, Budapest, and Milan. In 1932, Luft Hansa Junkers held a 49% interest in the company. Following its recovery from the Great Depression, the firm expanded its fleet by adding several Junkers Ju 52/3 m. The firm's rapid growth throughout the 1930s led to it becoming the fourth-largest airline in Europe at one point.

In 1938, the company began planning routes to Rome, Paris, and London, using a fleet of Junkers Ju 90 aircraft. Following the annexation of Austria by Nazi Germany in March 1938, these plans were promptly abandoned. From 1 January 1939, the airline was fully under the control of Lufthansa. Lufthansa deleted the company from the commercial register in June 1939.