Gianclaudio Giuseppe "Clay" Regazzoni (5 September 1939 – 15 December 2006) was a Swiss racing car driver. He competed in Formula One races from 1970 to 1980, winning five Grands Prix. His first win was the Italian Grand Prix at Monza in his debut season, driving for Ferrari. He remained with the Italian team until 1972. After a single season with BRM, Regazzoni returned to Ferrari for a further three years, 1974 to 1976.