Ireland competed at the 2012 Summer Olympics in London, United Kingdom, from 27 July to 12 August 2012. This was the nation's twentieth appearance at the Summer Olympics.

The Olympic Council of Ireland sent a total of 66 athletes to the Games, 36 men and 30 women, to compete in 14 sports. The International Olympic Committee allowed athletes from Northern Ireland the option to compete at the Olympic Games for either Great Britain or Ireland. Medallists Paddy Barnes and Michael Conlan were both born in Belfast, Northern Ireland and chose to compete for Team Ireland. Ireland had only a single competitor in the sprint canoeing, track cycling, equestrian dressage, judo, rowing and shooting events.

This was Ireland's most successful Olympics, winning a total of 5 medals (1 gold, 1 silver and 3 bronze) after left London in three sports: boxing, athletics and equestrian show jumping. Boxer Katie Taylor, who was Ireland's flag bearer at the opening ceremony, won Ireland's first Olympic gold medal in 16 years. Light flyweight boxer Paddy Barnes defended his bronze medal from Beijing, becoming the second Irish athlete in 80 years to win medals at two consecutive Olympics. For the first time since 1980, Ireland also won an Olympic medal in more than a single sport.

On 24 March 2016, race walker co-fourth placer Robert Heffernan was upgraded to bronze after the original gold medalist Sergey Kirdyapkin of Russia disqualified due to doping, that became a total of 6 medals.

Medallists

| width="78%" align="left" valign="top" | Medal Name Sport Event Date Katie Taylor Boxing Women's lightweight John Joe Nevin Boxing Men's bantamweight Cian O'Connor Equestrian Individual jumping Paddy Barnes Boxing Men's light flyweight Michael Conlan Boxing Men's flyweight Robert Heffernan Athletics Men's 50 kilometres walk | width="22%" align="left" valign="top" |

Medals by sportSport TotalBoxing 1 1 24Athletics 0 0 11Equestrian 0 0 11Total 1 1 4 6

International media coverage Katie Taylor's Olympic boxing success led to inaccurate coverage in the international media. While previewing her semi-final bout, The Daily Telegraph, a conservative English newspaper, incorrectly referred to Taylor as "British", prompting fierce criticism from other media outlets, and an apology from the Telegraph. Fairfax Media of Australia also issued an apology, after articles published in The Age, Brisbane Times and The Sydney Morning Herald were widely condemned as "lazy stereotyping" of the Irish. Irish Ambassador to Australia Noel White issued a formal complaint about the article's reliance on Guinness, whiskey and potatoes to make a story. USA Today was criticised after its article said: "Back home on the emerald-green isle, pints of Guinness flowed freely, perhaps enough to replenish the Irish Sea. The "punters" inside betting parlors [sic] wagered pounds [sic] as if they were bits of candy. It is not hyperbole to suggest that, when Taylor entered the ring, the weight of a prideful, scuffling nation rested on her muscular shoulders." Also, Australian commentator Russell Barwick provoked "fury" while on ESPN, comparing Team Ireland's independence from Team GB to Tasmanian athletes not performing for Australia.

Athletics

The Irish team selection caused a number of controversies. In the women's marathon Linda Byrne, Ava Hutchinson and Caitriona Jennings were selected while Maria McCambridge, who had also run the 'A' qualifying standard missed out on selection, as only three athletes from a nation may compete in the event. Additionally the deadline for qualification for the marathon had been changed to allow Barbara Sanchez, who holds dual Irish and French citizenship, a chance to qualify. The team for the women's 4 × 400 metres relay was changed after Joanna Mills won an appeal of her exclusion on the grounds of having a faster time than Catriona Cuddihy who had initially been selected.

Irish athletes achieved qualifying standards in the following athletics events (up to a maximum of 3 athletes in each event at the 'A' Standard, and 1 at the 'B' Standard):

Men Track & road events AthleteEventHeatSemifinalFinalResultRankResultRankResultRankPaul Hession200 m20.69 5Did not advanceCiarán O'Lionaird1500 m3:48.3513colspan=2 Did not advanceAlistair Cragg5000 m13:47.0117colspan=2 Did not advanceMark KenneallyMarathoncolspan=4 2:21:1357Robert Heffernan20 km walkcolspan=4 1:20:189Brendan Boyce50 km walkcolspan=4 3:55:0129Colin Griffincolspan=4 Robert Heffernancolspan=4 3:37:54 NR

Women Track & road events AthleteEventHeatSemifinalFinalResultRankResultRankResultRankJoanne Cuddihy400 m52.094 q51.885Did not advanceFionnuala Britton5000 m15:12.97 10colspan=2 Did not advance10000 mcolspan=4 31:46.7115Derval O'Rourke100 m hurdles12.91 4 q12.915Did not advanceStephanie Reilly3000 m steeplechase9:44.779colspan=2 Did not advanceJessie BarrClaire BerginMichelle CareyCatriona CuddihyJoanne CuddihyMarian Heffernan4 × 400 m relay3:30.556colspan=2 Did not advanceLinda ByrneMarathoncolspan=4 2:37:13 66Ava Hutchinsoncolspan=4 2:37:17 68Caitriona Jenningscolspan=4 3:22:11 107Olive Loughnane20 km walkcolspan=4 1:29:3913Laura Reynoldscolspan=4 1:31:0220

Field events AthleteEventQualificationFinalDistancePositionDistancePositionTori PenaPole vault—Did not advanceDeirdre RyanHigh jump1.8527Did not advance

Badminton

Ireland qualified two badminton players for the Games. Scott Evans competed in the men's singles and Chloe Magee in the women's singles.; each made their second appearance at an Olympic Games.

AthleteEventGroup stageEliminationQuarterfinalSemifinalFinal / OppositionScoreOppositionScoreRankOppositionScoreOppositionScoreOppositionScoreOppositionScoreRankScott EvansMen's singlesL 8–21 14–212Did not advanceChloe MageeWomen's singlesW 21–17 21–6L 21–16 18–21 14–212Did not advance

Boxing

Ireland qualified boxers for the following events.

Men AthleteEventRound of 32Round of 16QuarterfinalsSemifinalsFinalOppositionResultOppositionResultOppositionResultOppositionResultOppositionResultRankPaddy BarnesLight flyweightW 15–10W 23–18L 15–15+Did not advanceMichael ConlanFlyweightW 19–8W 22–18 L 10–20Did not advanceJohn Joe NevinBantamweightW 21–6W 15–10W 19–13W 19–14L 11–14Adam NolanWelterweightW 14–8L 9–18Did not advanceDarren O'NeillMiddleweightW 15–6L 12–19Did not advance

Women AthleteEventRound of 16QuarterfinalsSemifinalsFinalOppositionResultOppositionResultOppositionResultOppositionResultRankKatie TaylorLightweightW 26–15W 17–9W 10–8

Canoeing

Slalom Ireland qualified boats for the following events.

AthleteEventPreliminarySemifinalFinalRun 1RankRun 2RankTotalRankTimeRankTimeRankEoin RheinischMen's K-189.97690.721189.9712 Q153.9814Did not advanceHannah CraigWomen's K-1117.0714108.9911108.9914 Q116.1210 Q127.369

Sprint Ireland qualified boats for the following events.

AthleteEventHeatsSemifinalsFinalTimeRankTimeRankTimeRankAndrzej JezierskiMen's C-1 200 m41.4042 Q42.0124 FB44.0419 Qualification Legend: FA = Qualify to final (medal); FB = Qualify to final B (non-medal)

Cycling

Road AthleteEventTimeRankDan MartinMen's road race5:46:3790David McCannMen's road race5:46:3755Men's time trial56:03.7727Nicolas RocheMen's road race5:46:3789

Track Omnium AthleteEventFlying lapPoints raceElimination raceIndividual pursuitScratch raceTime trialTotal pointsRankTimeRankPointsRankRankTimeRankRankTimeRankMartyn IrvineMen's omnium13.5049476154:32:9481491:04:558116413

Equestrian

By rankings Ireland qualified one athlete in dressage, an eventing team and two athletes in jumping.

Dressage AthleteHorseEventGrand PrixGrand Prix SpecialGrand Prix FreestyleOverallScoreRankScoreRankTechnicalArtisticScoreRankAnna MerveldtCoryolanoIndividual69.77233Did not advance

Eventing AthleteHorseEventDressageCross-countryJumpingTotalQualifierFinalPenaltiesRankPenaltiesTotalRankPenaltiesTotalRankPenaltiesTotalRankPenaltiesRankAoife ClarkMaster CrusoeIndividual48.90323.6052.50210.0052.50120.0052.50752.507Mark KyleCoolio58.70617.2065.90356.0071.90324.0075.902175.9021Joseph MurphyElectric Cruise55.60531.8060.40290.0060.40240.0060.401460.4014Michael RyanBallylynch Adventure60.2064EliminatedDid not advanceCamilla SpeirsPortersize Just A Jiff47.6027EliminatedDid not advanceAoife ClarkMark KyleJoseph MurphyMichael RyanCamilla SpeirsSee aboveTeam152.101036.70178.8076.00184.805colspan=3 184.805

Show jumping AthleteHorseEventQualificationFinalTotalRound 1Round 2Round 3Round ARound BPenaltiesRankPenaltiesTotalRankPenaltiesTotalRankPenaltiesRankPenaltiesTotalRankPenaltiesRankCian O'ConnorBlue LoydIndividual01 Q8831 Q122038 Q01 Q112 JO1Billy TwomeyTinka442 Q81256Did not advance

Gymnastics

Ireland qualified a single gymnast for London; Kieran Behan, just the second Irish gymnast in history to qualify for the Olympics, competed in the artistic gymnastics discipline.

Artistic Men AthleteEventQualificationFinalApparatusTotalRankApparatusTotalRankKieran BehanFloor13.966colspan=5 13.96653Did not advance

Judo

AthleteEventRound of 32Round of 16QuarterfinalsSemifinalsRepechageFinal / OppositionResultOppositionResultOppositionResultOppositionResultOppositionResultOppositionResultRankLisa KearneyWomen's −48 kgL 0012–1011Did not advance

Modern pentathlon

Ireland qualified 2 athletes.

AthleteEventFencing(épée one touch)Swimming(200 m freestyle)Riding(show jumping)Combined: shooting/running(10 m air pistol)/(3000 m)Total pointsFinal rankResultsRankMP pointsTimeRankMP pointsPenaltiesRankMP pointsTimeRankMP pointsArthur Lanigan-O'KeeffeMen's14–21297362:02.44913328020112011:08.69262328551625Natalya CoyleWomen's19–16118562:19.17201132405116012:12.4513207252209

Rowing

Ireland qualified the following boats.

Women AthleteEventHeatsRepechageQuarterfinalsSemifinalsFinalTimeRankTimeRankTimeRankTimeRankTimeRankSanita PušpureSingle sculls7:49:353 QFcolspan=2 7:44:194 SC/D7:51.691 FC7:59.7713 Qualification Legend: FA=Final A (medal); FB=Final B (non-medal); FC=Final C (non-medal); FD=Final D (non-medal); FE=Final E (non-medal); FF=Final F (non-medal); SA/B=Semifinals A/B; SC/D=Semifinals C/D; SE/F=Semifinals E/F; QF=Quarterfinals; R=Repechage

Sailing

Ireland qualified 1 boat for each of the following events.

Men AthleteEventRaceNet pointsFinal rank234567895M*James EspeyLaser38443936464227272535EL31336Scott FlaniganGer Owens4701625242515222527165EL17323David BurrowsPeter O'LearyStar2 6 14 5 11 12 9 7 11 7 20 95 10

Women AthleteEventRaceNet pointsFinal rank12345678910M*Annalise MurphyLaser Radial1111819210375444

Open AthleteEventRaceNet pointsFinal rank123456789101112131415M*Matt McGovernRyan Seaton49er481521219119147157131616EL14914 M = Medal race; EL = Eliminated – did not advance into the medal race;

Shooting

Men AthleteEventQualificationFinalPointsRankPointsRankDerek BurnettTrap11627 did not advance

Swimming

Irish swimmers achieved qualifying standards in the following events (up to a maximum of 2 swimmers in each event at the Olympic Qualifying Time (OQT), and 1 at the Olympic Selection Time (OST)):

Men AthleteEventHeatSemifinalFinalTimeRankTimeRankTimeRankBarry Murphy50 m freestyle22.7629Did not advance100 m breaststroke1:01.5729Did not advance Qualifiers for the latter rounds (Q) of all events were decided on a time only basis, therefore positions shown are overall results versus competitors in all heats.

Women AthleteEventHeatSemifinalFinalTimeRankTimeRankTimeRankSycerika McMahon100 m breaststroke1:08.8026Did not advance200 m individual medley2:14.7622Did not advanceGráinne Murphy200 m freestyleDid not advance400 m freestyle4:19.0731colspan=2 Did not advance800 m freestylecolspan=2 Did not advance400 m individual medleycolspan=2 Did not advanceMelanie Nocher100 m backstroke1:02.4433Did not advance200 m backstroke2:16.2934Did not advance Qualifiers for the latter rounds (Q) of all events were decided on a time only basis, therefore positions shown are overall results versus competitors in all heats.

Triathlon

Ireland qualified the following athletes.