2003 Boston Red Sox season Game log May

| Date_ | Opponent | Score | Loss | Save_ |
|---|---|---|---|---|
| May 15 | Rangers | 12–3 | Benes (0–2) | ||33,801||26–14 |
| May 16 | Angels | 6–5 | Embree (2–1) | Percival (6) |
| May 17 | Angels | 6–2 | Timlin (3–2) | Percival (7) |
| May 18 | Angels | 5–3 | Lackey (2–4) | Person (1) |
| May 19 | Yankees | 7–3 | Fossum (4–2) | ||35,099||27–17 |
| May 20 | Yankees | 10–7 | Contreras (1–1) | Lyon (6) |
| May 21 | Yankees | 4–2 | Wakefield (4–2) | Rivera (4) |
| May 23 | Indians | 9–2 | Rodríguez (2–5) | ||32,673||29–18 |
| May 24 | Indians | 12–3 | Anderson (2–5) | ||32,643||30–18 |
| May 25 | Indians | 6–4 | Fossum (4–3) | Báez (9) |
| May 26 | @ Yankees | 8–4 | Clemens (6–3) | ||55,093||31–19 |
| May 27 | @ Yankees | 11–3 | Chen (0–1) | ||44,769||31–20 |
| May 28 | @ Yankees | 6–5 | Lyon (1–2) | ||44,617||31–21 |