F1: Formula 1 1991 Season Review

The 1991 FIA Formula One World Championship was the 45th season of FIA Formula One motor racing and the 42nd season of the Formula One World Championship. It featured the 1991 Formula One World Championship for Drivers and the 1991 Formula One World Championship for Constructors, which were contested concurrently over a sixteen-race series that commenced on 10 March and ended on 3 November. Ayrton Senna won his third and last Drivers' Championship, and McLaren-Honda won their fourth consecutive Constructors' Championship. Senna won seven of the sixteen races; his main challenger for the title was Nigel Mansell, who won five races in his first season back at Williams. Senna's fierce rival Alain Prost failed to win a race with Ferrari and was fired before the end of the season due to a dispute with the team. 1991 also saw the debuts of future world champions Michael Schumacher and Mika Häkkinen, as well as the retirement of three-time champion Nelson Piquet.

As of 2022, this is the last World Championship season to be won by a Brazilian racing driver, a V12-engined car, or a car equipped with a manual gearbox. As of 2022, it is also the last constructors' title won by a Honda-powered car (although the supplier Red Bull Powertrains who won the constructors' championship in 2022 used a Honda-based engine design and had Honda technical assistance), and it was the last drivers' championship to be won by a Honda-powered driver until Max Verstappen's Championship win in 2021.

Also, this was Pirelli's last season as the tyre supplier for the Formula One World Championship, until they returned the sport again in 2011, where they become the sole tyre supplier for the sport in that season.