The circuit was built with remarkable speed — 3,500 workers constructed it between May and July 1922, a period of just two months — financed by the Milan Automobile Club through a body it created specifically for the purpose, the Società Incremento Automobilismo e Sport. The site chosen lay within the grounds of the Royal Villa of Monza, a large park north of Milan.
The original layout combined a 4.490 km banked oval with a 5.500 km road course, capable of being run as a combined 10.000 km circuit via a shared front straight. The circuit was officially opened on 3 September 1922, and the second Italian Grand Prix followed on 10 September of the same year.
The presence of the banked oval distinguished Monza from virtually every other European road circuit of the era. The steep banking sections allowed cars to sustain flat-out speeds through corners that would otherwise have demanded braking, making the combined circuit among the fastest in the world. This configuration was in use through much of the 1920s and shaped Monza's reputation as the Temple of Speed, a designation that endured long after the prewar layout was retired.
Monza's prewar history was marked by a series of catastrophic accidents that forced repeated changes to the circuit. In 1928, the Italian Grand Prix ended in one of the worst disasters in racing history to that point when driver Emilio Materassi crashed his Talbot into a grandstand, killing him and 27 spectators. The event led immediately to the confinement of Grand Prix races to the high-speed oval loop, away from grandstand areas, until 1932.
The 1933 edition produced what became known as the Black Day of Monza. During the supporting Monza Grand Prix, held the same day as the Italian Grand Prix, three prominent drivers died in separate accidents on the shorter oval circuit: Giuseppe Campari driving an Alfa Romeo, Baconin Borzacchini in a Maserati, and Stanislaw Czaykowski in a Bugatti. The events shook the racing world and again prompted layout changes.
From 1934 onward, a succession of modified configurations was used, none entirely satisfactory. The 1934 layout introduced a short circuit with a hairpin joining the two lanes of the main straight and a double chicane at the Curva Sud, driven in the reverse of the usual direction. This arrangement was considered too slow and was replaced the following year by a return to the Florio Circuit layout, this time with four temporary chicanes added and a fifth permanent one. By 1938 only one permanent chicane at the Curva Sud remained.
A comprehensive rebuilding of the circuit took place in 1938 and 1939. New grandstands and entrance facilities were constructed, the track surface was resurfaced, the high-speed banked oval was removed, and two new bends were added to the southern part of the circuit. The result was a Grand Prix layout measuring 6.300 km, which remained in use from 1939 until 1954. The outbreak of the Second World War suspended racing before this new layout could be fully tested in competition, and parts of the circuit deteriorated through lack of maintenance and military use during the war years.
Through the 1930s Monza was the setting for battles between the great Italian and German manufacturers. Alfa Romeo, running its supercharged P3 and later Tipo B machinery, competed fiercely against the rising might of Mercedes-Benz and Auto Union, the latter backed by the Nazi government's desire to demonstrate German technological supremacy. Drivers including Tazio Nuvolari, Rudolf Caracciola, Achille Varzi, and Hans Stuck were regular protagonists in races at Monza during this period. The circuit's long straights favored raw engine power, meaning that each year's Italian Grand Prix served as a rough proxy for which nation's engineering had produced the most powerful machinery.
The prewar Monza circuit established the fundamental identity of the venue: fast, dangerous, situated in a parkland setting close to Milan, and deeply tied to the prestige of Italian motorsport. The high-speed oval was demolished in 1938 as part of the prewar redesign, but the concept of flat-out racing at the venue outlasted the physical banking. Monza retained its reputation for absolute speed through the entire postwar era, becoming the fastest circuit on the Formula One calendar — a character established directly by the decisions made about layout and purpose during the 1920s and 1930s.