| Irish Cup | |
| Year: | 1917–18 |
| Country: |  Ireland |
| Num Teams: | 11 |
| Defending Champions: | Glentoran |
| Winners: | Belfast Celtic (1st win) |
| Second: | Linfield |
| Matches: | 14 |
| Goals: | 36 |
| Prev Season: | 1916–17 |
| Next Season: | 1918–19 |
The 1917–18 Irish Cup was the 38th edition of the Irish Cup, the premier knock-out cup competition in Irish football.
Belfast Celtic won the tournament for the 1st time, defeating Linfield 2–0 in the second final replay after the previous two matches had ended in draws.[1] [2]
|}
|}
|}
|}
|}