The 1975 Formula One season was the 29th season of FIA Formula One motor racing. It featured the 1975 World Championship of F1 Drivers and the 1975 International Cup for F1 Manufacturers which were contested concurrently from 12 January to 5 October over fourteen races.

After a strong finish to the 1974 season, many observers felt the Brabham team were favourites to win the 1975 title. The year started well, with an emotional first win for Carlos Pace at the Interlagos circuit in his native São Paulo. However, over the season tyre wear frequently slowed the cars, and the initial promise was not maintained.

Niki Lauda often referred to 1975 as "the unbelievable year". In his second year with Ferrari, the team provided him with the Ferrari 312T – a car that was technically far superior to any of the competition. He won his first world title with five wins and a huge margin over second place in the championship.

American Mark Donohue died in August, two days after a practice run crash for the Austrian Grand Prix. After the season in late November, an Embassy Hill airplane crashed in England and all six aboard were killed, including team owner Graham Hill and driver Tony Brise.