The Race of Two Worlds (Trofeo dei Due Mondi in Italian), also known as the 500 Miglia di Monza (500 Miles of Monza), was an automobile race held at the Autodromo Nazionale Monza, Italy in 1957 and again in 1958. It was intended as an exhibition event, allowing American teams from the United States Auto Club (USAC) National Championship to compete directly against teams from the Formula One World Championship based in Europe. The two types of cars competed on the banked oval at Monza which had been completed in 1955. Due to the similarity to the Indianapolis Motor Speedway, where the USAC teams ran the Indianapolis 500, the event earned the nickname Monzanapolis.
American drivers and teams won the event in both the years in which it was run. Jimmy Bryan won the 1957 event, and Jim Rathmann swept the 1958 race. Although some Formula One teams did participate and even built special cars specifically for the event, several withdrew over safety concerns. Continued concern over the speeds on the track and the cost of the event led to the race being canceled after the 1958 running.