The 1998 Grand Prix motorcycle racing season was the 50th F.I.M. Road Racing World Championship season.

Season summary

Mick Doohan and Honda continued to dominate the 500 class with the Australian taking 8 victories and Honda winning all but one race. Simon Crafar winning the British Grand Prix for Yamaha's lone victory. After being shocked by 500 class rookie Max Biaggi's opening round victory in the Japanese Grand Prix, Doohan went on to claim his fifth world championship in as many years, finishing off the season with four consecutive wins. A controversial finish marked the 250 title race. Aprilia teammates Tetsuya Harada and Loris Capirossi both went into the final race in Argentina with a chance to win the title, Capirossi leading Harada by 4 points. With one corner to go, Harada was in second, with Capirossi third, which would have given Harada the championship on tiebreak. Entering the final turn, his bike was struck from behind by Capirossi's machine, sending both riders off the track. Valentino Rossi took the win with Capirossi recovering to finish in second and claiming the title. Afterwards, Aprilia would release Capirossi from his contract. Kazuto Sakata would win his second 125 title for Aprilia after a tight battle with Tomomi Manako and Marco Melandri.

1998 Grand Prix season calendar

The following Grands Prix were scheduled to take place in 1998: †† = Saturday race

Calendar changes

1998 Grand Prix season results

†† = Saturday race

Participants

500cc participants

Standings

Riders' standings

500cc

Points were awarded to the top fifteen finishers. A rider had to finish the race to earn points.

250cc

Points were awarded to the top fifteen finishers. A rider had to finish the race to earn points.

125cc

Points were awarded to the top fifteen finishers. A rider had to finish the race to earn points.

Manufacturers' standings

500cc

250cc

125cc