(pictured at the
Malaysian Grand Prix) set two records in his first two races:
youngest driver to start a race, and
youngest driver to score points.|alt=A picture of Max Verstappen driving a Toro Rosso TR10 during the 2015 Malaysian Grand Prix.
Pre-season Lewis Hamilton was the defending Drivers' Champion after securing his second title at the
2014 Abu Dhabi Grand Prix. His team,
Mercedes, began the season as the defending Constructors' Champion, having clinched its first championship title at the
2014 Russian Grand Prix. Before the start of the season, Hamilton announced he would not be exercising his option of switching his car number to 1 for 2015, as was his prerogative as reigning World Champion, and would instead race with his career number 44. It was the first season since , when
Alain Prost retired from the sport following his fourth and final World Drivers' Championship title in , that the field did not contain a number one car. Following the financial struggles faced by Marussia and Caterham in 2014, the FIA approved the use of 2014-specification chassis in 2015 provided that teams showed cause and received an individual dispensation to compete with their old chassis. A request by Manor Marussia to use their
2014 car was rejected by the other teams. Subsequent regulation changes allowed the team to use a modified 2014 chassis which met updated safety and dimensional limits.
The car was powered by a 2014 specification Ferrari power unit, with a new chassis to be introduced later in the season. McLaren's Fernando Alonso was involved in a pre-season testing accident that saw the two-time World Drivers' Champion hospitalised. McLaren claimed the crash was caused by a sudden gust of wind disrupting the car's downforce, while Alonso insisted the crash was caused by his steering wheel locking up. On physicians' advice, Alonso elected to sit out the opening round in Australia, prompting the team to replace him with Kevin Magnussen for the race. Alonso was cleared to race by the second round in
Malaysia.
Championship ,
Sebastian Vettel secured
Ferrari's first victory since the
2013 Spanish Grand Prix and his first victory since the
2013 Brazilian Grand Prix.|alt=A picture of Sebastian Vettel cheering on the podium after winning the 2015 Malaysian Grand Prix for Ferrari.
Opening rounds Mercedes began the season with a one–two finish in Australia, resulting in a twenty-eight-point lead after just one round. They finished over thirty seconds clear of Sebastian Vettel, who finished third and secured a podium finish in his first race with Ferrari. The team also voiced its displeasure over the progress Renault had made in terms of power, with the team principal,
Christian Horner, saying the Renault Energy F1-2015 was still down on Mercedes's PU106B Hybrid. After the race, the Red Bull team advisor
Helmut Marko suggested that Red Bull might exit Formula One entirely if changes to the regulations were not made to level the field or cut development costs. Renault countered with their own threat to pull out of Formula One as an engine supplier if its reputation continued to be damaged or if its participation was otherwise not profitable to the company. Mercedes followed up by finishing second and third in Malaysia, while Red Bull continued to struggle, rounding out the top ten a lap down. After four rounds, Mercedes led the field, having earned 159 points (with Lewis Hamilton acquiring 93 out of 100 possible points), while Red Bull's struggles continued. The team acquired twenty-six points, enough for a distant fourth, and Ricciardo entered the European stages of the season on his fourth and final permissible power unit with fifteen events remaining on the calendar. With McLaren's longest continuous testing session lasting twelve laps in
Montmeló – a total of , a sixth of a total Grand Prix distance – before running into engine trouble, Honda elected to detune the power units for the opening Grands Prix in an effort to improve reliability and longevity while the manufacturer worked to improve these areas before
homologation. After both cars qualified on the back row, Kevin Magnussen failed to reach the grid after suffering an abrupt engine failure while on his way from the pit lane to the grid.
Jenson Button managed to finish the race, albeit in the last classified position, two laps behind the leaders. Magnussen relinquished his seat back to Alonso in Malaysia; both cars qualified ahead of only the Manor Marussia cars and eventually retired. The team showed signs of improvement in terms of performance and was able to compete with the midfield cars in
China and
Bahrain, although reliability continued to prove troublesome as Button's car was unable to compete in the latter Grand Prix. Following a tumultuous pre-season in which they went through a period of administration and were saved by late investment, Manor Marussia arrived in Melbourne with a car that had passed its mandatory crash tests but had completed no testing. After the team's arrival in Australia, while assembling the cars, it was discovered that their computers had been wiped completely clean of all data in preparation for auction, and they ultimately could not compete in the Grand Prix. The team managed to get their cars running and on the racetrack by the second round in Malaysia, and were able to set times within
107% of the leading times in practice, giving stewards reasonable grounds to allow the team to race when they failed to do so in qualifying. Merhi was able to finish the race three laps down in fifteenth, while Stevens did not start. They were one of two teams, the other being McLaren, to return to Europe without a championship point. Ferrari came into the season seemingly much more competitive than the previous season, finishing on the podium in the opening race. In Malaysia, Vettel won comfortably and Räikkönen finished in fourth, despite suffering a tyre failure. With 107 points, the team returned to Europe 52 points behind Mercedes, and 46 points ahead of Williams, who were third.
European and Canadian rounds leads the field on the opening lap of the
Spanish Grand Prix. He would go on to win the race.|alt=A picture of the 2015 field of formula one cars negotiating the first turns during the 2015 Spanish Grand Prix. Mercedes arrived at
Spain already with a comfortable lead. Lewis Hamilton had scored ninety-three points out of a possible one hundred, giving him a twenty-seven-point lead over his teammate Nico Rosberg entering the eight-race European portion of the season. Rosberg quickly cut into Hamilton's championship lead by securing victories in Spain (reducing his deficit to twenty points) and
Monaco. The latter win was aided by the result of a costly miscalculation by the Mercedes team to pit Hamilton with a 19-second lead during a safety car period (that briefly saw the use of the "Virtual Safety Car" for the first time in F1's history) with 14 laps remaining. Rosberg and Sebastian Vettel did not make pit stops, allowing both to narrowly pass Hamilton by the pit lane exit. Racing resumed on lap seventy-one and Rosberg quickly pulled away, remaining in the lead until the chequered flag. Vettel held off Hamilton for second and third, respectively. As a result, Hamilton's lead over Rosberg in the Drivers' Championship was cut in half, to just ten points. Meanwhile, Button secured McLaren's first points of the season by finishing eighth. This left the Marussia drivers of Stevens and Merhi, along with the other McLaren driver, Fernando Alonso, as the only full-time drivers not to score a point after seven rounds. At the following Grands Prix in
Canada,
Austria, and
Britain, Mercedes put to rest the criticism following the result in Monaco through finishing first and second in the next three races, extending their championship lead to 160 points over Ferrari. Williams collected their first two podiums of the season in the form of third-place results by
Valtteri Bottas in Canada and
Felipe Massa in Austria, while Ferrari lost ground to Mercedes following a retirement in Austria and an eighth-place finish in Britain by Räikkönen. Honda continued to have reliability issues and, up to the British Grand Prix, suffered nine retirements and two failures to start due to power unit problems, translating to only seven overall finishes out of 18 possible results. The Drivers' Championship remained closely contested between leader Lewis Hamilton and Nico Rosberg, with the gap between them never larger than twenty-eight points after Hamilton's victory in round eleven in
Belgium. The two would trade victories between rounds six and nine, closing the gap to as little as ten points. Sebastian Vettel, who at one time was within three points of the lead, after his victory in Malaysia, and who was the only non-Mercedes winner after eleven rounds, could not overcome team errors in Canada and Austria, and fell fifty-nine points off the pace of Hamilton after round nine. He rebounded in
Hungary by winning his second race of the season, reducing the gap to Hamilton to forty-two points in the process, but fell out of a point-scoring position in Belgium after a tyre failure on the penultimate lap, dropping him to sixty-seven points behind the leader. Hamilton closed out the European portion of the season with his seventh victory of the season in
Italy. With Rosberg's retirement at the event, Hamilton entered the closing rounds of the season with a lead of fifty-three points over his teammate in the Drivers' Championship standings, the largest gap of the season at that point, while Vettel sat a further twenty-one points behind. Hamilton's tenth pole position in Belgium assured him of victory in the FIA Pole Trophy, the award for the driver who achieves the most pole positions during the season. Mercedes had built up a 181-point lead over Ferrari in the Constructors' Championship, with Williams in third, 263 points behind the leaders. After twelve rounds, half of the teams had been represented on the podium, while nine out of ten had scored points. Vettel won his third victory of the season in Singapore, closing his gap to Nico Rosberg in second place to just eight points. Rosberg could not close the gap to Hamilton in
Japan or Russia; despite winning pole position in both races, his leads were short-lived. He was passed by Hamilton on the opening corner in Japan A victory in
the United States, with Rosberg and Vettel finishing second and third respectively, secured the third Drivers' Championship for Hamilton with three races left to run. Rosberg won the final three races in
Mexico,
Brazil, and Abu Dhabi to reclaim second in the Drivers' Championship from Vettel, while Hamilton secured the Fastest Lap Award in Brazil.
Awards Lewis Hamilton ended the season winning not only the championship, but also the FIA Pole Trophy for most pole positions of the season and the DHL Fastest Lap Award. Ferrari won the inaugural DHL Pit Stop Award, posting the fastest pit stop time at seven of the first eighteen races of the season. Both Hamilton and Mercedes collected their championship trophies at a gala held in Paris on 4 December 2015. Toro Rosso's Max Verstappen collected three post-season awards for Rookie of the Year, Personality of the Year and Action of the Year (for his overtake on Felipe Nasr through
Blanchimont corner at the Belgian Grand Prix).
Legal disputes Sauber Sauber's early season preparations were disrupted by a series of legal challenges from the former Caterham driver
Giedo van der Garde, who claimed the team had reneged on a contract that was signed in June 2014. Van der Garde filed a motion with the
Supreme Court of Victoria in Australia in an effort to force the team to replace one of their drivers with him at the opening round in Melbourne, with the court finding in his favour. Van der Garde later agreed not to participate in the event, with the driver and team settling the dispute for an undisclosed sum and terminating the contract following the first round.
Lotus Lotus suffered financially throughout the season, culminating in
Pirelli withholding their tyres for the Friday practice sessions in Hungary. Before the Belgian Grand Prix, amid negotiations with Renault for a potential takeover, the former Lotus reserve driver
Charles Pic initiated legal action against Lotus alleging lack of seat time in 2014, resulting in breach of contract. Belgian authorities later moved to impound the assets of Lotus for four days following Grosjean's podium finish. After talks between the FIA and Lotus, the team was allowed to leave Spa with their equipment and cars, and was able to start the following race in Italy. ==Results and standings==