| Hirobumi Watarai | |
| Position: | Infielder/Outfielder |
| Bats: | Right |
| Throws: | Right |
| Birth Date: | 26 January 1972 |
| Birth Place: | Funabashi, Chiba, Japan |
| Debutdate: | April 3 |
| Debutyear: | 1998 |
| Debutteam: | Yakult Swallows |
| Debutleague: | NPB |
| Finaldate: | October 12 |
| Finalyear: | 2008 |
| Finalteam: | Tokyo Yakult Swallows |
| Finalleague: | NPB |
| Statleague: | NPB |
| Stat1label: | Batting average |
| Stat1value: | .245 |
| Stat2label: | Hits |
| Stat2value: | 173 |
| Stat3label: | Home runs |
| Stat3value: | 9 |
| Stat4label: | RBI |
| Stat4value: | 61 |
| Stat5label: | Stolen bases |
| Stat5value: | 2 |
| Teams: | As player
As coach
|
is a Japanese former professional baseball infielder. He played in Nippon Professional Baseball (NPB) for the Tokyo Yakult Swallows from 1994 to 2008.
His son is Ryūki Watarai, a professional baseball player for the Yokohama DeNA BayStars.