Development on the Re.2005 began in 1941, with the preliminary design work already being completed by the end of the year, despite the fact that the aircraft was a completely new design and independent of previous Reggiane projects. The Re.2005 was part of Italy’s Serie 5 fighter program, and like the competing G.55 and C.205, was meant to be fitted with the Daimler-Benz DB605 engine or its respective Italian licence-built version - the FIAT RA.1050 RC.58 Tifone.

The prototype of the Re.2005 first flew on 9 May 1942, with subsequent test flights showing very promising results. Despite not deeming the Re.2005 as the all round best of the serie 5 aircraft (that honor went to the G.55 due to its easier manufacturing process), the Regia Aeronautica still put forward an order for 750 Re.2005s to be built. The Re.2005 was officially commissioned into service with the Regia Aeronautica in Spring 1943, formally receiving its nickname “Sagittario” (Archer, Sagittarius) upon entering service.

After its introduction, the Re.2005 primarily saw action above Italy, taking part in the defense of Sicily as well as protecting major cities against air raids such as Naples and Rome. Some units also served with the Luftwaffe by the end of the war, however, Re.2005s only saw limited use in general due to only few being built.

In fact, only a few dozens of Re.2005s managed to be produced by June 1943 due to the limited capacities of the crippled Italian war industry in the later stages of WWII - a far cry of the initially 750 ordered machines.