Masahiro Shimizu (清水 雅広, Shimizu Masahiro, born November 22, 1964) is a Japanese former professional Grand Prix motorcycle road racer.

Originally from Fujisawa, Kanagawa Prefecture, Shimizu won the 1987 250cc All Japan Road Race Championship.

[1] He began his Grand Prix career with a win in 1987.

His best season was in 1991, when he finished fifth in the 250cc world championship, riding on a Honda.

[2] Points system from 1969 to 1987: Points system from 1988 to 1992: (key) (Races in bold indicate pole position; races in italics indicate fastest lap)