Ireland competed at the 1976 Summer Olympics in Montreal, Quebec, Canada. 44 competitors, 41 men and 3 women, took part in 34 events in 10 sports. Cearbhall Ó Dálaigh did not attend the Olympics in Montreal due to the African boycott.
Archery
In Ireland's first appearance in archery competition at the Olympics, the nation was represented by one man, James Conroy.
Men's Individual Competition:
- James Conroy – 2255 points (→ 29th place)
Athletics
Men's 800 metres
- Niall O'Shaughnessy
:* Heat – 1:49.29 (→ did not advance)
Men's 1.500 metres
- Eamon Coghlan
:* Heat – 3:39.87
:* Semifinal – 3:38.60
:* Final – 3:39.51 (→ 4th place)
- Niall O'Shaughnessy
:* Heat – 3:40.12 (→ did not advance)
Men's 5.000 metres
- Edward Leddy
:* Heat – 13:40.54 (→ national record, did not advance)
Men's 10.000 metres
- Edward Leddy
:* Heat – 28:55.29 (→ did not advance)
Men's Marathon
- James McNamara – 2:24:57 (→ 39th place)
- Danny McDaid – 2:27:07 (→ 42nd place)
- Neil Cusack – 2:35:47 (→ 55th place)
Women's 1.500 metres
- Mary Purcell
:* Heat – 4:08.63 (→ national record, did not advance)
Boxing
Men's Light Flyweight (– 48 kg)
- Brendan Dunne
- First Round – Defeated Noboru Uchizama (JPN), RSC-2
- Second Round – Lost to Orlando Maldonado (PUR), KO-1
Canoeing
Cycling
Two cyclists represented Ireland in 1976.
;Individual road race
- Alan McCormack – did not finish (→ no ranking)
- Oliver McQuaid – did not finish (→ no ranking)
Equestrian
Rowing
;Men's single sculls
- Seán Drea 4th place in the Final (→ 4th)
;Men's coxless fours
- Martin Feeley 2nd in repechage (→ unplaced)
- Iain Kennedy 2nd in repechage (→ unplaced)
- Andy McDonough 2nd in repechage (→ unplaced)
- Jaye Renehan 2nd in repechage (→ unplaced)
;Men's coxed fours
- Jim Muldoon 1st in B Final (→ 7th)
- Christy O'Brien 1st in B Final (→ 7th)
- Willie Ryan 1st in B Final (→ 7th)
- Mick Ryan 1st in B Final (→ 7th)
- Liam Redmond 1st in B Final (→ 7th)
Sailing
Shooting
Swimming
;Men
{| class=wikitable style="font-size:90%;"
|-
!rowspan=2|Athlete
!rowspan=2|Event
!colspan=2|Heat
!colspan=2|Semifinal
!colspan=2|Final
|- style="font-size:95%"
!Time
!Rank
!Time
!Rank
!Time
!Rank
|-align=center
|rowspan=3 align=left|Kevin Williamson
|align=left|200 m freestyle
| 2:00.08
| 41
| colspan=2
| colspan=2 | Did not advance
|-align=center
|align=left|400 m freestyle
| 4:09.60
|
| colspan=2
| colspan=2 | Did not advance
|-align=center
|align=left|1500 m freestyle
| 16:54.11
|
| colspan=2
| colspan=2 | Did not advance
|-align=center
|rowspan=2 align=left|Robert Howard
|align=left|100 m backstroke
| 1:00.77
|
| colspan=4 | Did not advance
|-align=center
|align=left|100 m butterfly
| 1:00.92
|
| colspan=4 | Did not advance
|}
;Women
{| class=wikitable style="font-size:90%;"
|-
!rowspan=2|Athlete
!rowspan=2|Event
!colspan=2|Heat
!colspan=2|Semifinal
!colspan=2|Final
|- style="font-size:95%"
!Time
!Rank
!Time
!Rank
!Time
!Rank
|-align=center
|rowspan=3 align=left|Deirdre Sheehan
|align=left|100 m freestyle
| 1:02.11
|
| colspan=4 | Did not advance
|-align=center
|align=left|200 m freestyle
| 2:15.69
|
| colspan=2
| colspan=2 | Did not advance
|-align=center
|align=left|100 m backstroke
| 1:11.53
|
| colspan=4 | Did not advance
|-align=center
|align=left|Miriam Hopkins
|align=left|200 m butterfly
| 2:24.96
|
| colspan=2
| colspan=2 | Did not advance
|}