Chassis Mt4 #1113-1115 and Tipo G #4501, 4502 are produced 1951
- April 29th – 1951 Mille Miglia, OSCA wins 1st, 2nd, and 3rd in class (1100 Sport)
- OSCA experiments with coupe styling, using both Frua and Vignale as designers and coachbuilders.
- Cabianca wins the Italian championship driving an OSCA Mt4
- During 1951 OSCA participates in 39 races, winning 21!
- As a result of a GP formula change, OSCA Formula 1 effort seizes after manufacturing two cars and three engines,