The Ferrari 312PB was a sportcar prototype racing car of the early 1970s. It was officially designated the 312P, but often known as the 312PB to avoid confusion with a previous car of the same name. It was part of the Ferrari P series of sports prototypes. In 1970, a change in the regulations for sportscar racing for 1972 was announced. The loophole for the big 5L sports cars (such as the Porsche 917 and Ferrari 512) was closed, and the minimum weight of the 3L prototypes was raised to 650 kg (1433 lb).