The FAI Cup 2005 was the 85th staging of The Football Association of Ireland Challenge Cup or FAI Cup. It officially kicked off in late April, when twenty clubs from the junior and intermediate leagues battled it out for the chance to face League of Ireland opposition in the second round. The ten winners of those ties were joined in the second round by the 22 eircom League of Ireland clubs. The competition ran until early December, with the final taking place on Sunday, December 4.
Matches played on the weekend of Saturday, 24 April 2005.
Matches played on the weekend of Sunday, 12 June 2005.
Matches played on the weekend of Sunday, 28 August 2005.