1958 Grand Prix motorcycle racing season

The 1958 Grand Prix motorcycle racing season was the tenth F.I.M. Road Racing World Championship Grand Prix season. The season consisted of seven Grand Prix races in five classes: 500cc, 350cc, 250cc, 125cc and Sidecars 500cc. It began on 6 June, with Isle of Man TT and ended with Nations Grand Prix in Italy on 14 September.

At the end of the 1957 season, Gilera, Mondial, Moto Guzzi and MV Agusta announced a multilateral withdrawal from GP racing, due to economic reasons and rising public pressure due to the large amount of fatal motorsport accidents occurring in Italy during the previous years. MV Agusta reverted their decision several days later. This situation left reigning 500cc champion Libero Liberati and reigning 250cc champion Cecil Sandford without rides for 1958.

A major technical change for 1958 was the ban of dustbin fairings - streamlined bodywork that covered front wheels - in all classes. They were used by most entrants by the end of 1957, including privateers. As of 2023, the rule is still in place in MotoGP.

1958 Grand Prix season calendar
† The Nations Grand Prix also held a non-championship 175 cc race, won by the Italian, Francesco Villa.

Scoring system
Points were awarded to the top six finishers in each race. Only the four best races counted in 125cc, 250cc, 350cc and 500cc championships, while in the Sidecars the three best results were counted.