The circuit was built between May and July 1922 by 3,500 workers, financed by the Milan Automobile Club through a body it created specifically for the purpose: the Società Incremento Automobilismo e Sport (SIAS). The original layout occupied a 3.4 km² site within the Royal Villa of Monza park, comprising a paved 4.490 km (2.790 mi) oval and a 5.500 km (3.418 mi) road course, which could be combined into a 10.000 km (6.214 mi) circuit via their shared front straight. The track officially opened on 3 September 1922; the second Italian Grand Prix followed on 10 September 1922. Monza's proximity to Milan — Italy's economic capital and largest metropolitan area — made it a naturally convenient location.
The 1928 Italian Grand Prix brought the most serious Italian racing accident to that point: driver Emilio Materassi and 27 spectators were killed when his car crashed into the grandstand. Grand Prix races were subsequently confined to the high-speed loop until 1932, and the Italian Grand Prix itself was not held again until 1931.
The 1933 Italian Grand Prix became known as the "Black Day of Monza" after the deaths of three drivers — Giuseppe Campari, Baconin Borzacchini, and Stanisław Czaykowski — during the supporting Monza Grand Prix held on the oval circuit the same day. Layout changes followed in 1934 and subsequent years, including the introduction of chicanes and modified circuit sections.
Major rebuilding in 1938–39 constructed new stands, resurfaced the track, removed the high-speed ring, and added two new bends on the southern part, producing a 6.300 km (3.915 mi) Grand Prix lap used until 1954. World War II suspended racing until 1948; the circuit was renovated over two months at the start of that year.
In 1954, a major revamp produced the current 5.750 km (3.573 mi) road course and a new 4.250 km (2.641 mi) high-speed oval with banked sopraelevata curves. The two could be combined into the former 10.000 km (6.214 mi) circuit. Formula One used the combined high-speed layout in the 1955, 1956, 1960, and 1961 Grands Prix.
The Automobile Club of Italy staged the Race of Two Worlds on the oval in 1957 and 1958, pitting USAC IndyCars against European Formula One and sports cars in three 267.67 km (166.32 mi) heat races per year. Only Ecurie Ecosse and Maserati represented Europe in the first running; the Maserati entries withdrew after their steering was compromised by the larger Firestone tyres needed for the banked surface. American cars dominated both years.
The 1961 Italian Grand Prix ended the oval's use for Formula One when Wolfgang von Trips collided with Jim Clark's Lotus approaching the Parabolica; von Trips' car became airborne and struck the barriers, killing him and fifteen spectators. The combined circuit was attempted once more in 1963 before teams protested against its extreme bumpiness and the event reverted to the road circuit. The banking has not been used for major races since the 1969 1000 km of Monza; it fell into decay, was restored in the 2010s, and is now used once a year for the Monza Rally Show.
In 1972, two chicanes — the Variante del Rettifilo and the Variante Ascari — were added to reduce speeds, producing a new circuit length of 5.755 km (3.576 mi). Grand Prix motorcycles continued to use the unmodified road track until two serious accidents in 1973, including the deaths of Renzo Pasolini and Jarno Saarinen, ended motorcycle racing at Monza for eight years. Further modifications in 1974, 1976, and 1979 added another chicane before the Lesmo and extended run-off areas.
Following the deaths of Ayrton Senna and Roland Ratzenberger at Imola in 1994, the three main long curves were tightened to install larger gravel traps, shortening the lap to 5.770 km (3.585 mi). In 2000, the chicane on the main straight was reconfigured; a fire marshal, Paolo Gislimberti, was killed at that race by flying debris. Gravel at the second chicane was replaced by asphalt in 2007. Ahead of the 2024 Italian Grand Prix, the entire circuit was resurfaced and facility improvements carried out; as a result, the WEC's 6 Hours of Monza was relocated to Imola.
Monza is currently the fastest permanent circuit on the Formula One calendar, a status it has held since 1991. With only six corner complexes, Formula One cars run at full throttle for nearly 80% of the lap, placing exceptional demands on engines. The circuit demands minimum downforce setups to reduce drag on the straights, creating low-grip conditions where understeer is a serious concern.
During the 2025 Italian Grand Prix, Max Verstappen set the fastest ever pole position lap at Monza with a time of 1:18.792 at an average speed of 264.681 km/h (164.465 mph) — the fastest average qualifying lap in World Championship history. The race lap record of 1:20.901 was set by Lando Norris at the same event.
Over its history, the Autodromo Nazionale Monza has been the site of 52 driver and 35 spectator fatalities.
Beyond Formula One, Monza has hosted the 1,000 km Monza endurance race (part of the World Sportscar Championship and later the European Le Mans Series), the Race of Two Worlds, the FIA World Endurance Championship 6 Hours of Monza (2021–2023), the Superbike World Championship, the Monza Rally Show, and numerous junior single-seater and GT championships. In 2020, Monza hosted the ACI Rally Monza, the final round of that year's World Rally Championship, with the circuit used for 10 of the 16 stages.