The 2008–09 Irish Cup was the 129th edition of the Irish Cup, Northern Ireland's premier football knock-out cup competition. The competition began on 25 October 2008 with the first round and ended on 9 May 2009 with the final.
Linfield were the defending champions, winning their third consecutive Irish Cup the previous season after a 2–1 win over Coleraine in the 2008 final. This season they reached the semi-finals, but were defeated by Cliftonville. Crusaders went on to lift the trophy, beating Cliftonville 1–0 in the final. In doing so, they earned a place in the second qualifying round of the 2009–10 UEFA Europa League.[1][2]
The matches were played on 25 October and 1 November 2008.
The games were played on 22 November 2008.
In this round entered winners from the Second Round as well as all 17 teams from IFA Championship. The games were played on 13 December 2008.
In this round entered winners from the Third Round as well as all 12 teams from IFA Premiership. The games were played on 17 January 2009.
In this round entered the sixteen winners from the Fourth Round. The matches were played on 14 February 2009.