Aidan O’Brien

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Welcome to our profile of leading Irish Trainer Aidan O’Brien.

Irish horse racing trainer Aidan Patrick O’Brien was born in County Wexford, Ireland, on October 16, 1969.

He has served as John Magnier and his associates from the Coolmore Stud’s private trainer at Ballydoyle Stables near Rosegreen in County Tipperary since 1996.

When Saxon Warrior won the Racing Post Trophy at Doncaster, O’Brien broke Bobby Frankel’s 2003 record of 25 by training 26 Group or Grade 1 winners in a single calendar year. O’Brien increased the record to 28 at the year’s end.

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Key Stats of Trainer Aidan O’Brien

Aidan O’Brien – Trainer Profile

Aidan O’Brien is a son of small-scale racehorse trainer Denis and he gained further experience with P.J. Finn and later Jim Bulger.

He briefly took over the yard of father-in-law Joe Crowley in 1993, becoming champion National Hunt trainer in Ireland in 1993-1994. He would retain that title for five seasons, taking the helm for leading owner John Magnier at Ballydoyle in 1996.


Istabraq helped to establish O’Brien’s reputation as the rising star in the Irish training ranks with three Champion Hurdle victories.

His first Group 1 success on the flat came with Desert King in the 1996 National Stakes, the same horse providing him with a maiden Classic win in the Irish 2000 Guineas the following season.

In 2001 he emulated legendary trainer Vincent O’Brien by being crowned Champion Trainer in Britain.

Aidan O’Brien – Key Trainer Stats

O’Brien recorded his first century in a calendar year in 1997 with 116 winners.

His best year numerically was in 2018 with 154 winners.

That eclipsed his previous best tally of 139 in 2013.

His 103 winners in a compressed 2020 season was his eighth consecutive ton and the eleventh of his career.

He was Champion Trainer in Britain for the first time in 2001 and retained the title in 2002. He also claimed the title in 2007, 2008, 2016 and 2017.

O’Brien was Champion National Hunt trainer in Ireland for five successive seasons from 1992-93 to 1997-98.

He topped the Irish Champion Flat figures for the first time in 1997.

Dermot Weld took the crown in 1998 but O’Brien has dominated every year since, claiming a remarkable 22nd consecutive title in 2020.

Aidan O’Brien’s Big Race Wins

For all the many Classic winners trained by O’Brien, perhaps two of his most famous stars remain three-time Champion Hurdle winner Istabraq and four-time Ascot Gold Cup winner Yeats.

Istabraq won the Champion Hurdle at Cheltenham in 1998, 1999 and 2000 but was denied a possible fourth victory when the 2001 meeting was lost to the outbreak of foot and mouth.

He also won four Irish Champion Hurdles in the colours of JP McManus.

Yeats was favourite for the 2004 Epsom Derby but met with an injury after winning the Derrinstown Stud Derby Trial. He returned as a four-year-old, winning the Coronation Cup and the Irish St Leger. He came into his own as a Gold Cup horse in 2006, going on to win the Ascot Gold Cup for a record four successive seasons.

O’Brien is a multiple winner of all the English and Irish Classic races.

Horses to stand out here include Galileo (2001), High Chaparral (2002) and Australia (2014), all winners of both the English and Irish Derby. Famous milers include Rock of Gibraltar and Giant’s Causeway. Rock of Gibraltar won both the English and Irish 2000 Guineas in 2002 and recorded seven consecutive Group 1 victories.

Giant’s Causeway was runner-up in both Classics but won five straight Group 1’s and gained a reputation as “The Iron Horse”.

Aidan O’Brien’s – Most Famous Victories

There have been so many great races and famous victories for O’Brien that it is almost impossible to narrow it down to a handful of winners.

Rock of Gibraltar’s 2000 Guineas win at Newmarket Racecourse came at the expense of heavily-backed stable companion Hawk Wing.

Rock of Gibraltar would go on to become 2002 European Horse of the Year whereas Hawk Wing would top the World Thoroughbred Rankings in 2003. His 11 lengths win in the Lockinge Stakes at Newbury Racecourse earned a Timeform rating of 136, the highest recorded over a mile for ten years.

High Chaparral won the Breeders’ Cup Turf in 2002 and 2003, the first horse to win the race twice. His 2003 victory involved a thrilling three-way photo with the verdict being a dead-heat between High Chaparral and Johar.

St Nicholas Abbey was a terrific flagbearer for Ballydoyle, winning three Coronation Cups and taking a memorable 2011 Breeders’ Cup Turf.

Other famous names to pass through Ballydoyle include Dylan Thomas, Camelot, Highland Reel, Minding, Found and Magical.

Summary of Aidan O’Brien

Aidan O’Brien continues to break all records in Ireland and Great Britain, mopping up Classic races and Group 1 events.

With sons Joseph and Donnacha already making their mark in the training ranks, the O’Brien name looks set to dominate for a long time to come.

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