| Masafumi Hirai | |
| Position: | Pitcher / Coach |
| Team: | Orix Buffaloes |
| Number: | 72 |
| Birth Date: | 21 April 1975 |
| Bats: | Right |
| Throws: | Right |
| Debutleague: | NPB |
| Debutdate: | September 10 |
| Debutyear: | 1994 |
| Debutteam: | Orix BlueWave |
| Finalleague: | NPB |
| Finaldate: | June 8 |
| Finalyear: | 2014 |
| Finalteam: | Orix Buffaloes |
| Statleague: | NPB |
| Stat1label: | Win–loss record |
| Stat1value: | 63-43 |
| Stat2label: | ERA |
| Stat2value: | 3.31 |
| Stat3label: | Strikeouts |
| Stat3value: | 620 |
| Stat4label: | Saves |
| Stat4value: | 41 |
| Stat5label: | Holds |
| Stat5value: | 84 |
| Teams: | As player
As coach
|
| Awards: | |
Masafumi Hirai (平井 正史, born April 21, 1975, in Uwajima, Ehime Prefecture) is a Japanese former professional baseball pitcher. Hirai played in Japan's Nippon Professional Baseball for the Orix BlueWave/Buffaloes from to and from to and the Chunichi Dragons from to .