The 1991 Japanese motorcycle Grand Prix was the first round of the 1991 Grand Prix motorcycle racing season. It took place on the weekend of 22–24 March 1991 at the Suzuka Circuit.
Mick Doohan (3) is followed by Kevin Schwantz (34), Wayne Rainey (1) and John Kocinski (19) in the 500 cc race.
Martin Wimmer in the 250 cc race.