| Tournament details | |
|---|---|
| Country |  Republic of Ireland | 
| Teams | 42 | 
| Final positions | |
| Champions | Derry City | 
| Runner-up | St Patrick's Athletic | 
| Tournament statistics | |
| Matches played | 49 | 
| Goals scored | 134 (2.73 per match) | 
The FAI Cup 2006 was the 86th staging of The Football Association of Ireland Challenge Cup or FAI Cup. This season's competition was the last to be sponsored by Carlsberg. 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 League of Ireland clubs. The competition ran until early December, with the final taking place on Sunday, December 3.
First round
Fixtures played weekend April 23
Waterford Crystal 4-1 Garda AFC
Castlebar Celtic 5-1 Fairview CYM
Ashtown Villa 2-2 Wayside Celtic
Tolka Rovers 1-3 Carrigaline United
College Corinthians2-2 Blarney United
Brendanville 0-1 Douglas Hall
Malahide United 1-1 Fanad United
Athenry 0-0 Bangor Celtic
Killester United 6-1 St Mochtas
Second round
Matches played on the weekend of Sunday, 28 May 2006.
| Tie no | Home team | Score | Away team | 
|---|---|---|---|
| 1 | Longford Town | 2-1 | Cork City | 
| 2 | Athlone Town | 2-1 | Galway United | 
| 3 | Bohemians | 3-1 | Waterford Crystal | 
| 4 | Bray Wanderers | 2-2 | Kildare County | 
| replay | Kildare County | 0-1 | Bray Wanderers | 
| 5 | Waterford United | 5-0 | Douglas Hall | 
| 6 | Limerick | 0-0 | Drogheda United | 
| replay | Drogheda United | 0-1 | Limerick | 
| 7 | Dundalk | 1-0 | Cobh Ramblers | 
| 8 | Blarney United | 1-3 | Derry City | 
| 9 | Bangor Celtic | 1-3 | Shelbourne | 
| 10 | Carrigaline United | 0-4 | Sligo Rovers | 
| 11 | Kilkenny City | 0-2 | UCD | 
| 12 | Dublin City | 0-0 | Monaghan United | 
| replay | Monaghan United | 2-4 | Dublin City | 
| 13 | Finn Harps | 1-0 | Crumlin United | 
| 14 | Castlebar Celtic | 0-2 | Shamrock Rovers | 
| 15 | Malahide United | 0-2 | St Patrick's Athletic | 
| 16 | Wayside Celtic | 0-1 | Killester United | 
Third round
Matches played on the weekend of Sunday, 27 August 2006.
| Tie no | Home team | Score | Away team | 
|---|---|---|---|
| 1 | Shamrock Rovers | 1-1 | Bohemians | 
| replay | Bohemians | 0-2 | Shamrock Rovers | 
| 2 | Waterford United | 1-1 | Longford Town | 
| replay | Longford Town | 1-0 | Waterford United | 
| 3 | UCD | 3-1 | Limerick | 
| 4 | St Patrick's Athletic | 2-0 | Dundalk | 
| 5 | Finn Harps | 0-0 | Athlone Town | 
| replay | Athlone Town | 3-2 | Finn Harps | 
| 6 | Sligo Rovers | 2-1 | Bray Wanderers | 
| 7 | Shelbourne | 0-1 | Derry City | 
| 8 | Killester United | w/o | Dublin City | 
Quarter-finals
Matches played on the weekend of Sunday, 1 October.
| St Patrick's Athletic | 4–1 | Longford Town | 
|---|---|---|
| Molloy  3',  61',  78' pen Foley  26' pen | Martin  69' | 
| Athlone Town | 1–2 | Shamrock Rovers | 
|---|---|---|
| Sheridan  38' | Rowe  82' Clarke  90' | 
| Sligo Rovers | 0–0 | Killester United | 
|---|---|---|
| Derry City | 2–0 | UCD | 
|---|---|---|
| Farren  65' pen McHugh  67' | 
Replay
| Killester United | 3–4 aet | Sligo Rovers | 
|---|---|---|
| Keogh  19',  77' Lacey  51' | Bellew  11' Hughes  44' Peers  67' McTiernan  102' | 
Semi-finals
| Shamrock Rovers | 0–2 | St Patrick's Athletic | 
|---|---|---|
| Keegan  18', Molloy  ?' | 
Replay
| Derry City | 5–0 | Sligo Rovers | 
|---|---|---|
| McCourt  33', Farren  39'(pen),  46', Martyn  42',  91' | 
Final
The 2006 FAI Cup Final was the last at the old Lansdowne Road.
| Derry City | 4-3 (AET) | St Patrick's Athletic | 
|---|---|---|
| M. Farren  25' C. Delaney  84' P. Hutton  106' S. Brennan (OG)  109' | FAI Cup final 2006 Match Report | D. Mulcahy  19' T. Molloy (pen)  74' S. O'Connor  103' | 
| Winner of FAI Cup 2006 | 
|---|
| Derry City 4th Title |