The 2009 Japanese motorcycle Grand Prix was the second round of the 2009 Grand Prix motorcycle racing season. It took place on the weekend of 24–26 April 2009 at the Twin Ring Motegi, located in Motegi, Japan. The MotoGP race was the 700th premier class race in the history of Grand Prix motorcycle racing. Jorge Lorenzo won the MotoGP race ahead of teammate Valentino Rossi to take the overall lead in the world championship.

The 2009 Grand Prix motorcycle racing season was the 61st F.I.M. Road Racing World Championship season. The season consisted out of 17 races for the MotoGP class and 16 for the 125cc and 250cc classes, beginning with the Qatar motorcycle Grand Prix on 12 April 2009 and ending with the Valencian Community motorcycle Grand Prix on 8 November.