2005 Seattle Mariners season Game log May

| Date_ | Opponent | Score | Loss | Attendance | Record |
|---|---|---|---|---|---|
| May 1 | @ Athletics | 3–2 | Piñeiro (2–2) | 30634 | 12–13 |
| May 2 | Anaheim | 5–0 | Franklin (1–4) | 24184 | 12–14 |
| May 3 | Anaheim | 5–2 | Meche (2–2) | 29917 | 12–15 |
| May 4 | Anaheim | 5–2 | Sele (2–3) | 26303 | 12–16 |
| May 6 | @ Red Sox | 7–2 | Moyer (4–1) | 35229 | 12–17 |
| May 7 | @ Red Sox | Postponed, rescheduled for 8 May | Postponed, rescheduled for 8 May | Postponed, rescheduled for 8 May | 12–17 |
| May 8 | @ Red Sox | 6–3 | Piñeiro (2–3) | 34848 | 12–18 |
| May 8 | @ Red Sox | 6–4 | Halama (1–1) | 34671 | 13–18 |
| May 9 | @ Yankees | 4–3 | Nelson (0–1) | 38079 | 13–19 |