Valentino Rossi led the championship for almost the entire season as he chased a tenth world title, but ultimately, the honors went to his Yamaha Motor Racing teammate Jorge Lorenzo, who took his third MotoGP title and a fifth world title overall. Lorenzo started the season quietly with three finishes off the podium, whereas Rossi took wins in Qatar and Argentina.
2015 was the final season that Bridgestone was the sole tire supplier for MotoGP, as Michelin became the sole tire 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.