Fiat G.59

G.55 Centauro
The second prototype G.55, MM 492, in Regia Aeronautica markings
Role	Fighter
National origin	Italy
Manufacturer	Fiat
Designer	Giuseppe Gabrielli
First flight	30 April 1942
Introduction	1943
Status	Retired
Primary users	Regia Aeronautica Aeronautica Nazionale Repubblicana Argentine Air Force Royal Egyptian Air Force
Produced	274 (wartime), 75 (postwar)
Unit cost	L. 535.000 (L. 1.284.000 for planned 2.400 aircraft)

The Fiat G.55 Centauro (Italian: "Centaur") was a single-engine single-seat World War II fighter aircraft used by the Regia Aeronautica and the A.N.R. (Aeronautica Nazionale Repubblicana) in 1943-1945. It was designed and built in Turin by Fiat. The Fiat G.55 was probably the best type produced in Italy during World War II, (a subjective claim also frequently made for the Macchi C.205 Veltro as well as for the Reggiane Re.2005 "Sagittario") but it did not enter production until 1943, when, after comparative tests against the Messerschmitt Bf 109G and the Focke-Wulf 190, the Luftwaffe itself regarded the Fiat G.55 as "the best Axis fighter".

During its short operational service, mostly under the Repubblica Sociale Italiana insignia, after the 8 September 1943 armistice, this powerful, robust and fast aircraft proved itself to be an excellent interceptor at high altitude. In 1944, over Northern Italy, the Centauro clashed with British Supermarine Spitfire, P-51 Mustang, P-47 Thunderbolt and P-38 Lightning, proving to be no easy adversary. Italian fighter pilots liked their Centauro but by the time the war ended, fewer than 300 had been built. By comparison, the Germans produced 34,000 Bf 109s.

By 1939, all the main Italian aircraft factories had begun designing a new series of monoplane fighter aircraft, using inline engines as opposed to the radial engines that powered the first generation Italian monoplane fighters used in the early years of World War II (fighters such as the Fiat G.50 and the Macchi C.200). This process saw the first generation radial-engined fighters re-equipped with the Italian-built copy of the Daimler-Benz DB 601 engine, the so-called Serie 1/2, whose most prominent representative was the Macchi C.202 Folgore (which was simply a Macchi C.200 with an inline V-12 instead of a radial engine). Aircraft in this series were given alphanumeric designations ending in the number "2". However, the process didn't stop, and already in 1941, designers shifted their attention on the new, larger and more powerful Fiat RA.1050, a license-built copy of the Daimler-Benz DB 605. Aircraft powered by this new engine became the "Serie 5", and all had alphanumeric designations ending in the number "5" (Macchi C.205, Reggiane Re.2005, Fiat G.55). Fiat designer Giuseppe Gabrielli, while experimenting a new version of his Fiat G.50 fighter, equipped with the DB 601, started a new design that was to be powered by the Daimler-Benz DB 605.