The 2017 FIA Formula One World Championship was the 71st season of Formula One motor racing. It featured the 68th Formula One World Championship, a motor racing championship for Formula One cars which is recognised by the sport's governing body, the Fédération Internationale de l'Automobile (FIA), as the highest class of competition for open-wheel racing cars. Teams and drivers competed in twenty Grands Prix—starting in Australia on 26 March and ending in Abu Dhabi on 26 November—for the World Drivers' and World Constructors' championships. As the reigning Drivers' Champion Nico Rosberg announced his retirement from the sport in December 2016, the 2017 season was the first since 1994 in which the reigning champion did not compete. Mercedes started the season as the defending Constructors' Champion, having secured their third consecutive title at the 2016 Japanese Grand Prix.