The McLaren MP4-27 was a Formula One racing car designed by Vodafone McLaren Mercedes for the 2012 Formula One season. The car was driven by former World Champions Jenson Button and Lewis Hamilton. It was launched on 1 February at the McLaren team base in Woking, Surrey, ahead of the first winter test sessions at Jerez de la Frontera. This was the last McLaren car that Lewis Hamilton drove for the team, as he moved to the Mercedes AMG Petronas F1 Team in 2013. As of January 2017^[update], it is also the last car made by McLaren to achieve a race victory.

The car achieved 7 wins, 8 poles and third place in the Constructors' Championship in 2012.

The MP4-27 was one of three 2012 cars not to have the so-called "platypus" nose, instead opting for a gradual sloped nose. The Marussia F1 MR01 and HRT F112 also had a similar low nose; the F112 featured a less pronounced step in the nose of the car compared to others on the grid, however, incorporating the two ideas of regulation compliance into the same car.

After the struggles McLaren experienced in the build-up to the 2009 and 2011 seasons, the MP4-27 demonstrated early promise in testing. This was confirmed at the first race of the season in Australia, when Lewis Hamilton and Jenson Button qualified first and second for the race, the team's first since the 2009 European Grand Prix. Button went on to win the race, with Hamilton finishing third despite team principal Martin Whitmarsh's admission that the team had made a mistake in calculating Button's fuel load, forcing the 2009 World Champion to enter a "severe fuel-saving mode" on the eighth lap of the race.

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