2003 Boston Red Sox season Game log May

| Date_ | Opponent | Score | Loss | Save_ |
|---|---|---|---|---|
| May 1 | Royals | 6–5 | Grimsley (1–2) | Lyon (2) |
| May 2 | Twins | 11–7 | Mendoza (1–1) | ||31,317||19–10 |
| May 3 | Twins | 9–1 | Fiore (1–1) | ||33,061||20–10 |
| May 4 | Twins | 9–4 | Timlin (3–1) | ||32,887||20–11 |
| May 5 | @ Royals | 7–6 | Lyon (1–1) | ||21,232||20–12 |
| May 6 | @ Royals | 7–3 | Affeldt (2–1) | ||15,848||21–12 |
| May 7 | @ Royals | 9–6 | Lopez (4–1) | Lyon (3) |
| May 9 | @ Twins | 5–0 | Martínez (3–2) | ||28,436||22–13 |
| May 10 | @ Twins | 6–5 | Rincón (1–1) | Lyon (4) |
| May 11 | @ Twins | 9–8 | Lowe (3–3) | Guardado (8) |
| May 13 | Rangers | 5–4 | Cordero (1–4) | Lyon (5) |
| May 14 | Rangers | 7–1 | Benoit (1–1) | ||32,485||25–14 |