The 2005 British motorcycle Grand Prix was the ninth round of the 2005 MotoGP Championship. It took place on the weekend of 22–24 July 2005 at the Donington Park circuit. It was also marked the final victory of Valentino Rossi in the wet race at the British circuit until the 2015 event was held at the Silverstone Circuit.

The 2005 Grand Prix motorcycle racing season was the 57th 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 Spanish motorcycle Grand Prix on 10 April and ending with the Valencian Community motorcycle Grand Prix on 6 November.