Who is the only rider to have won the MotoGP championship on both a Yamaha and a Honda?

Valentino Rossi is the only rider to have won the MotoGP championship on both Yamaha and Honda.

Rossi won the premier-class title with Honda in 2002 and 2003, during the transition from the 500cc era to the four-stroke MotoGP era. He then made one of the sport’s most famous manufacturer changes, leaving Honda for Yamaha after the 2003 season.

The move immediately paid off. Rossi won the 2004 championship for Yamaha, becoming the first rider to win consecutive premier-class races with different manufacturers, and retained the title in 2005. He later added Yamaha championships in 2008 and 2009.

A common mix-up is Casey Stoner, who won titles for Ducati and Honda, or Jorge Lorenzo, who won for Yamaha. Rossi’s Honda titles came before his Yamaha success, making his achievement especially notable in an era when factory machinery was highly influential.