The McLaren MP4-27 is a Formula One racing car designed by Vodafone McLaren Mercedes for the 2012 Formula One season. The car is being driven by former World Champions Jenson Button and Lewis Hamilton. It launched on 1 February at the McLaren team base in Woking, Surrey, ahead of the first winter test sessions at Jerez de la Frontera.

The MP4-27 is 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 have a similar low nose; the F112 does feature 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.

Jenson Alexander Lyons Button MBE (born 19 January 1980) is a British Formula One driver currently signed to McLaren. He was the 2009 World Drivers' Champion for Brawn GP.

Button began karting at the age of eight and achieved early success, before progressing to car racing in the British Formula Ford Championship and the British Formula Three Championship. He first drove in Formula One with the Williams team for the 2000 season. The following year he switched to Benetton, which in 2002 became Renault, and then for the 2003 season he moved to BAR. They were subsequently renamed Honda for the 2006 season, during which Button won his first Grand Prix in Hungary, after 113 races.

Following the withdrawal of Honda from the sport in December 2008, he was left without a drive for the 2009 season, until Ross Brawn led a management buyout of the team in February 2009, and Button suddenly found himself in a highly competitive, Mercedes-engined car. He went on to win a record-equalling six of the first seven races of the 2009 season, securing the World Drivers' Championship at the Brazilian Grand Prix, having led on points all season; his success also helped Brawn GP to secure the World Constructors' Championship. For 2010, he moved to McLaren, partnering fellow British racer and former World Champion Lewis Hamilton. After finishing fifth for the team in 2010, Button finished the 2011 season as runner-up.

Lewis Carl Davidson Hamilton,MBE (born 7 January 1985) is a British Formula One racing driver from England, currently racing for the McLaren team. He is the 2008 Formula One World Champion.

Hamilton was born in Stevenage, Hertfordshire. In December 1995, at the age of ten, he approached McLaren team principal Ron Dennis at the Autosport Awards ceremony and told him, "I want to race for you one day ... I want to race for McLaren." Less than three years later McLaren and Mercedes-Benz signed him to their Young Driver Support Programme. After winning the British Formula Renault, Formula Three Euroseries, and GP2 championships on his way up the racing career ladder, he drove for McLaren in 2007, making his Formula One debut 12 years after his initial encounter with Dennis. Lewis Hamilton's contract for the McLaren driver development program made him the youngest ever driver to secure a contract which later resulted in an F1 drive.

Coming from a mixed-race background, with a black father and white mother, Hamilton is often labelled "the first black driver in Formula One", although Willy T. Ribbs tested an F1 car in 1986. He is also the first driver of black heritage to win a major race at Indianapolis Motor Speedway in any discipline.