The 1989–90 Irish Cup was the 110th edition of the Irish Cup, Northern Ireland's premier football knock-out cup competition.

It began on 20 January 1990 and concluded on 5 May 1990 with the final.

[1] Ballymena United were the defending champions after winning their 6th Irish Cup last season, defeating Larne 1–0 in the 1989 final.

[2] However, this season they went out in the first round to Dungannon Swifts.

[3] With the exception of the below teams, all other winning teams from the second round were given a bye into the fourth round.