The 2015 FIM MotoGP World Championship was the premier class of the 67th F.I.M. Road Racing World Championship season. The championship was won by Spanish rider Jorge Lorenzo, racing for Movistar Yamaha MotoGP. It was his third and final world title in the MotoGP category, his fifth overall in Grand Prix motorcycle racing. The season had 18 races, beginning in Qatar and finishing in Valencia, which determined who would be world champion between Movistar Yamaha teammates Lorenzo and runner-up Valentino Rossi. It was first time since 2013 that the world title was decided on the final race of the season. Lorenzo also had the most pole positions, fastest laps and race wins throughout the season; while Rossi had the most finishes, completing every race throughout the season, while Lorenzo had one race retirement in San Marino.
2015 was the final season that Bridgestone was the sole tyre supplier for MotoGP, as Michelin became the sole tyre supplier for the 2016 season.
The 2015 season also saw the début of the Suzuki GSX-RR and Aprilia RS-GP. The GSX-RR previously made an appearance at the 2014 Valencian Grand Prix ahead of a full-season return for Suzuki as a factory team for the first time since 2011 and the RS-GP was used by Gresini Racing after the team split from Honda at the end of last season.
This season is well known for the Sepang clash, which involved a collision between two-time defending champion Marc Márquez and then-championship leader, Rossi. The clash remains one of the most memorable and controversial moments in the sport's history, with Rossi's penalty (a grid demotion in Valencia) for the incident helping Lorenzo win the race in Valencia and clinch his third MotoGP world title.