The 1978 Formula One season was the 32nd season of FIA Formula One motor racing. It featured the 1978 World Championship of F1 Drivers and the International Cup for F1 Constructors, contested concurrently over a sixteen race series which commenced on 15 January and ended on 8 October.

Mario Andretti won the Drivers' World Championship, driving for JPS-Lotus. He remains the last American driver to win the World Championship. His victory at the Dutch Grand Prix is also the last for an American driver. Ronnie Peterson was awarded second place in the Drivers' standings posthumously, having died from medical complications after an accident at Monza during the Italian Grand Prix. JPS-Lotus won the International Cup for F1 Constructors.

Championship defendants Niki Lauda and Ferrari had parted ways late in 1977, and both parties struggled to repeat the successes they had enjoyed the previous seasons. Carlos Reutemann finished third in the championship in the lead Ferrari, while Lauda finished fourth with Brabham. Apart from Peterson's death, the year saw another tragedy when Peterson's Swedish compatriot Gunnar Nilsson died from cancer, having been forced to cut his career short after the previous season because of the disease.