| Tatsushi Masuda | |
| Position: | Pitcher |
| Team: | Saitama Seibu Lions |
| Number: | 14 |
| Bats: | Right |
| Throws: | Right |
| Birth Date: | 23 April 1988 |
| Birth Place: | Sumoto, Hyōgo, Japan |
| Debutdate: | June 13 |
| Debutyear: | 2013 |
| Debutteam: | Saitama Seibu Lions |
| Statyear: | 2023 season |
| Statleague: | NPB |
| Stat1label: | Win–loss record |
| Stat1value: | 31-38 |
| Stat2label: | Earned run average |
| Stat2value: | 3.01 |
| Stat3label: | Strikeouts |
| Stat3value: | 477 |
| Stat4label: | Saves |
| Stat4value: | 194 |
| Stat5label: | Holds |
| Stat5value: | 106 |
| Teams: |
|
| Awards: |
|
is a Japanese professional baseball pitcher for the Saitama Seibu Lions of Nippon Professional Baseball (NPB).