1975 Grand Prix motorcycle racing season

Giacomo Agostini would claim his final 500cc World Championship aboard a Yamaha two-stroke machine.

[1] Despite Michel Rougerie scoring more points, his Harley-Davidson teammate Walter Villa would take the 250cc title because of the "best of six finishes" rule.

[1] Nineteen-year-old newcomer Johnny Cecotto made an impressive debut at the season opening French Grand Prix where, he won the 250cc and 350cc races.

The Championship was not resolved until the tenth and final round in Czechoslovakia, when Agostini emerged triumphant to claim his fifteenth world title and the first in the premier 500cc class for a two-stroke motorcycle.

The writing was on the wall for four-stroke machinery as eight of the top ten riders in the points standings were aboard two-stroke machines.