Glentoran | European Cup | Competitions
| Season | 1 | 2 | 3 | 4 | G | W‑D‑L | GF‑GA | Reached |
|---|---|---|---|---|---|---|---|---|
| 1988‑89 | 0‑2 | 1‑1 | 2 | 0‑1‑1 | 1‑3 | 1st Round | ||
| 1981‑82 | 1‑1 | 4‑0 | 0‑2 | 2‑1 | 4 | 2‑1‑1 | 7‑4 | Round of 16 |
| 1977‑78 | 0‑1 | 2‑0 | 0‑1 | 0‑5 | 4 | 1‑0‑3 | 2‑7 | Round of 16 |
| 1970‑71 | 1‑3 | 0‑1 | 2 | 0‑0‑2 | 1‑4 | 1st Round | ||
| 1968‑69 | 0‑3 | 2‑2 | 2 | 0‑1‑1 | 2‑5 | 1st Round | ||
| 1967‑68 | 1‑1 | 0‑0 | 2 | 0‑2‑0 | 1‑1 | 1st Round | ||
| 1964‑65 | 2‑2 | 2‑3 | 2 | 0‑1‑1 | 4‑5 | 1st Round | ||
| Glentoran seasons in Champions League. Home games in bold. | ||||||||