Faugheen, one of jump racing's most popular horses, has been retired along with his Willie Mullins-trained stablemates Douvan and Benie Des Dieux.
The trio all won at the Cheltenham Festival for owner Rich Ricci.
Faugheen, nicknamed 'The Machine', took the Champion Hurdle in 2015 having won the Neptune Hurdle at Cheltenham under Ruby Walsh a year earlier.
He was third, aged 12, in the Marsh Chase, behind winner Samcro at the 2020 Cheltenham Festival.
That proved to be his last race and followed three victories earlier in the season, including an emotional triumph at Leopardstown that earned the horse a huge ovation from the crowd.
"Not always the most elegant at a hurdle or a fence, he was a trier and knew he was a dude," Ricci told the Sun.
"My favourite memory was of his Grade One novice chase win at the 2020 Dublin Racing Festival. The noise and the sprinting of the crowd to the parade ring was something I will never forget."
Douvan was unbeaten in 13 races after joining Mullins in 2014, a run that included the Supreme Novices' Hurdle and Arkle Trophy at Cheltenham, before twice disappointing in the Queen Mother Champion Chase.
Benie Des Dieux won the Mares' Hurdle at Cheltenham in 2018 and looked set to follow up a year later, with Walsh on board, before a dramatic fall at the last.