The 2005 FIA Formula One World Championship was the 59th season of FIA Formula One motor racing. It featured the 56th FIA Formula One World Championship, contested over a then-record 19 Grands Prix. It commenced on 6 March 2005 and ended 16 October.

Fernando Alonso and the Renault team won the World Drivers' and World Constructors' championships, ending five years of dominance by Michael Schumacher and Ferrari since 2000 and also ending nine years of Ferrari, McLaren and Williams dominance triopoly since 1996. Alonso's success made him the youngest champion in the history of the sport, a title he held until Lewis Hamilton's 2008 title success. Renault's win was their first as a constructor. Alonso started the season off strongly, winning three of the first four races and his title success was in little doubt. He sealed the title in Brazil with two races left after a controlled third-place finish. Alonso's championship was also the first for a Renault-powered driver since Jacques Villeneuve's championship in 1997.

2005 Formula One World Championship

Alonso and Renault had to contend with the pace of the resurgent McLaren team with lead driver Kimi Räikkönen outshining teammate Juan Pablo Montoya, who came highly regarded from his time at Williams. Räikkönen won seven races like Alonso but would have won more if not for a series of reliability issues, resulting in qualifying engine change penalties and retirements from the lead on three occasions. Nevertheless, Räikkönen grabbed the headlines winning from near the back of the grid in Japan, passing Alonso's Renault teammate Giancarlo Fisichella on the final lap. Reigning champions Michael Schumacher and Ferrari had a poor season by their standards, with Bridgestone unable to compete with Michelin after the tyre-change ban that only affected the 2005 season. Their only win came when Michelin deemed their own tyres unsafe after several incidents in the oval turn at Indianapolis. As a result, only the six Bridgestone cars took part. Schumacher just held on for third in the Drivers' Championship, in spite of the superior pace of McLaren, underlining the disappointing season Montoya had. The Colombian missed two races early on due to a tennis injury. He then won three races, showing glimpses of pace, but was well beaten by his teammate Räikkönen in the championship.

2005 Formula One World Championship

The 2005 season was the last before the Minardi, BAR and Jordan teams were taken over by new owners and changed names to Toro Rosso, Honda, and Midland respectively in the season. The former Jaguar team was sold from Ford to Red Bull GmbH and made its debut as Red Bull Racing during the 2005 season.

2005 Formula One World Championship

Teams and drivers

The following teams and drivers were competitors in the 2005 FIA Formula One World Championship.

† All engines were 3.0-litre, V10 configuration. 2005 was the final year of this engine formula. No Michelin-shod cars participated in the United States Grand Prix for safety reasons, leaving just six cars on the grid at the start of the race.

Free practice drivers

Five constructors entered free practice only drivers over the course of the season. Sauber Petronas were also eligible to enter a free practice driver, but elected not to do so.

Team changes

Red Bull Racing, which took over the Jaguar team, ran with Cosworth engines. Red Bull's lead driver was veteran Scotsman David Coulthard, paired with Christian Klien, the 2004 Jaguar driver. Toyota-powered Jordan Grand Prix was purchased by Midland Group, although the team continued as Jordan until 2006. Sauber switched from Bridgestone to Michelin tyres over the winter, further severing their ties with the Ferrari team. The BAR team was banned from the Grands Prix in Spain and Monaco, after both their cars were found to be underweight at the San Marino Grand Prix. At the Hungarian Grand Prix, West McLaren Mercedes became Team McLaren Mercedes. Shortly after the United States Grand Prix, Peter Sauber announced that Credit Suisse had sold BMW their majority share in his Sauber team, which announced its intention to run as BMW's factory team in 2006.