The Ferrari 642, also known as the Ferrari F1-91, was Scuderia Ferrari's challenger in the 1991 Formula One season. Designed by Steve Nichols and Jean-Claude Migeot, it was an evolution of the previous year's 641 chassis, which had contended for the championship. The 642, driven by notable drivers like Jean Alesi and Alain Prost, achieved its best result with Prost's second-place finish at the 1991 United States Grand Prix in Phoenix. Despite starting the season with championship aspirations, the 642 was replaced by the Ferrari 643 during the French Grand Prix, marking its relatively short stint in the competitive 1991 season.