The Fiat G.55 entered service in 1943 and was considered one of the best Axis fighters of the time. It was fast, capable of 385 m.p.h., and agile, with good stability at all altitudes.

The Series 0 was armed with 4 x 12.7mm machine guns and 1 x 20mm cannon. The Series 1 had 2 x 12.7mm machine guns and 3 x 20mm cannon. There was provision for 2 x 160Kg bombs to be carried. A torpedo variant was also produced.

The G.55A also served post-war with the Italian, Argentinian, Syrian, and Egyptian Air Forces.