1978 Toronto Blue Jays season Game log May

| Date_ | Opponent | Score | Loss | Record |
|---|---|---|---|---|
| May 2 | @ Athletics | 2–1 | Underwood (0–3) | 8–14 |
| May 3 | @ Athletics | 11–3 | Clancy (1–2) | 8–15 |
| May 5 | @ Mariners | 9–1 | Jefferson (1–4) | 8–16 |
| May 6 | @ Mariners | 6–0 | Lemanczyk (0–6) | 8–17 |
| May 7 | @ Mariners | 9–7 | Willis (0–2) | 8–18 |
| May 8 | Athletics | Postponed (rain) Rescheduled for July 21 | Postponed (rain) Rescheduled for July 21 | Postponed (rain) Rescheduled for July 21 |
| May 9 | Athletics | 4–0 | Broberg (4–1) | 9–18 |
| May 10 | Athletics | 3–1 | Langford (0–2) | 10–18 |
| May 12 | Mariners | 8–3 | Rawley (0–3) | 11–18 |
| May 13 | Mariners | 9–6 | Lemanczyk (0–7) | 11–19 |