The 1966 Italian Grand Prix was a Formula One motor race held at Monza on 4 September 1966. It was race 7 of 9 in both the 1966 World Championship of Drivers and the 1966 International Cup for Formula One Manufacturers. The race was the 36th Italian Grand Prix and the 32nd to be held at Monza. The race was held over 68 laps of the five kilometre circuit for a race distance of 391 kilometres.

The 1966 Formula One season was the 20th season of FIA Formula One motor racing. It featured the 17th World Championship of Drivers, the 9th International Cup for F1 Manufacturers, and four non-championship races open to Formula One cars. The World Championship was contested over nine races between 22 May and 23 October 1966.