| Hiromi Oka | |
| Position: | Outfielder |
| Team: | Chiba Lotte Marines |
| Number: | 25 |
| Bats: | Right |
| Throws: | Right |
| Birth Date: | 15 July 1991 |
| Birth Place: | Kurashiki, Okayama, Japan |
| Debutleague: | NPB |
| Debutdate: | March 28 |
| Debutyear: | 2014 |
| Debutteam: | Hokkaido Nippon-Ham Fighters |
| Statyear: | July 21, 2024 |
| Statleague: | NPB |
| Stat1label: | Batting average |
| Stat1value: | .244 |
| Stat2label: | Home runs |
| Stat2value: | 40 |
| Stat3label: | Runs batted in |
| Stat3value: | 179 |
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is a Japanese professional baseball outfielder for the Chiba Lotte Marines of Nippon Professional Baseball (NPB). Oka is known as person that he has the same name as heroine of Aim for the Ace!, Japanese animation. Oka is outfielder but he had worn No. 18, it is known as uniform number that great pitcher wear in Japanese professional baseball, from 2017 to 2018.