The Royal Italian Air Force (Italian: Regia Aeronautica Italiana, RAI) was the air force of the Kingdom of Italy. It was established as a service independent of the Royal Italian Army from 1923 until 1946. In 1946, the monarchy ended and the Kingdom of Italy became the Italian Republic, whereupon the name of the air force changed to Aeronautica Militare.

At the beginning of the twentieth century, Italy was at the forefront of aerial warfare: during the colonization of Libya in 1911, it made the first reconnaissance flight in history on 23 October, and the first ever bombing raid on 1 November.

During World War I, the Italian Corpo Aeronautico Militare, then still part of the Regio Esercito (Royal Army), operated a mix of French fighters and locally built bombers, notably the gigantic Caproni aircraft. The Regia Marina (Royal Navy) had its own air arm, operating locally built flying boats.

The Italian air force became an independent service—the Regia Aeronautica—on 28 March 1923. Benito Mussolini's fascist regime turned it into an impressive propaganda machine, with its aircraft, featuring the Italian flag colors across the full span of the undersides of the wings, making numerous record-breaking flights. Between 1 April 1939 (I think 1 April 1939 is an error - it must have been an earlier year - as this paragraph talks of records in 1933 and 1934 below) and 1 November 1939, Italian airmen established no fewer than 110 records, winning world championships in round trips, long-range flights, high speed and altitude flights. After successful long-range flights around the Mediterranean Sea, Charles Lindbergh's successful transatlantic flight in the Spirit of St. Louis inspired the Regia Aeronautica to embark on a longer transatlantic voyage with stops in West Africa and Brazil. Possibly the most brilliant successes were the floatplane world speed record of 709 km/h (440.6 mph) achieved by Francesco Agello in the Macchi-Castoldi MC-72 in October 1934 and the long-range formation flight to the United States and back to Italy in 1933, a total of 19,000 km (11,800 miles) with Savoia-Marchetti S.55 flying boats. This Decennial Air Cruise included stops in Amsterdam, Derry, Reykjavík, Labrador, Montreal, Chicago, Brooklyn, and Washington D.C., with the highlight being a landing in Lake Michigan in front of Chicago Navy Pier and a procession through the city before crowds of thousands of Americans to coincide with the Century of Progress Exhibition. This pioneering achievement was organized and led by General of Aviation Italo Balbo.

During the latter half of the 1930s, the Regia Aeronautica participated in the Spanish Civil War, as well as the invasions of Ethiopia and Albania.

The first test for the new Italian Royal Air force came in October 1935, with the Second Italo-Ethiopian War. During the final stages of the war, the Regia Aeronautica deployed up to 386 aircraft, operating from Eritrea and Somalia. The Italian aviators did not have any opposition in the air, as the Imperial Ethiopian Air Force had just 15 transport and liaison aircraft, only nine of which were serviceable. However, the Regia Aeronautica lost 72 planes and 122 aircrew while supporting the operations of the Regio Esercito, sometimes dropping poison gas bombs against the Ethiopian army. After the end of hostilities on 5 May 1936, for the following 13 months the Regia Aeronautica had to assist Italian forces in fighting Ethiopian guerrillas.

During the Spanish coup of July 1936, Italian pilots in Spanish Foreign Legion uniforms airlifted Francisco Franco's Army of Africa from Spanish Morocco to the Spanish mainland. During the Spanish Civil War Italian pilots fought alongside Spanish Nationalist and German Luftwaffe pilots as members of the Aviazione Legionaria ("Aviation Legion"). This deployment took place from July 1936 to March 1939 and complemented an expeditionary force of Italian ground troops called the "Corps of Volunteer Troops". In Spain, the Italian pilots were under direct command of the Spanish Nationalists and took part in training and joint operations with the pilots of the German "Condor Legion". Mussolini sent to Spain 6000 aviation personnel as well as about 720 aircraft, including 80-90 Savoia-Marchetti SM 81, 100 Savoia Marchetti SM.79 bombers and 380–400 Fiat CR.32 biplanes that dominated the air, proving superior to the Soviet Polikarpovs of the Spanish Republican Air Force. The Aviazione legionaria achieved approximately 500 aerial victories, losing 86 aircraft in air combat and about 200 flying personnel. But more important than the material losses were the wrong conclusions drawn from air war in Spain. The Air Ministry, blinded by the success of the Fiat CR.32, persisted in its belief that the biplane could still dominate the sky, and ordered large numbers of Fiat CR.42 Falcos, the last war biplane in history.

The Regia Aeronautica played a limited role during the Italian invasion of Albania in 1939.^{[citation needed]}