The 2007 Grand Prix motorcycle racing season was the 59th Road Racing World Championship season. The 2007 season was significant as it introduced a new regulation which specifies that competitors in the MotoGP class can use up to 800 cc motorcycles; between 2002 and 2006, competitors had been allowed to use 990 cc motorcycles. While the 800cc motorcycles have less power than their 990cc counterparts, their ability to brake later and carry more speed through turns due to their lighter weight allowed them to break lap records in pre-season testing.
Casey Stoner won the MotoGP title, winning 10 of the 18 races to finish with a lead of 125 points over second placed Dani Pedrosa. Jorge Lorenzo won his second 250cc title, and Gábor Talmácsi won the 125cc title.
Stoner had a massive breakthrough season on the Ducati, the team winning its first world title on the Grand Prix scene. It was also the first time since 1973 that the premiere category had not been won by a Japanese constructor. The new 800 cc Ducati engine had a significant advantage over the other manufacturers in straightline speed but was tricky to ride through corners for Stoner's experienced teammate Loris Capirossi. Stoner was in strong contention early on but Valentino Rossi was very close for a long period of the season, before Stoner started to pull away at mid-season and sealed his title with several races to go, with Rossi's title challenge fading.
Up to the end of 2006, speculation suggested that Honda would have the advantage of the new 800cc engines, as they could modify their existing engines easier than other manufacturers. In practice, Honda suffered the most from the regulation change, with only Dani Pedrosa and Marco Melandri making any impression on the leaders. Stoner scored a string of wins for Ducati, Suzuki saw Chris Vermeulen take their first win since the advent of four-stroke regulations and John Hopkins posted his first podium finish. The Kawasaki team also made progress with improved results.