Treacy called it a day after finishing third on Dermot Weld’s Vigil in the Thorntons Recycling Maiden Hurdle at Leopardstown on Saturday.
He rode Tom Foley’s Danoli to victory in the Denny Gold Medal Chase and the Irish Hennessy in the 1996-97 season.
Some of his other notable successes included Native Upmanship’s Champion Novice Hurdle win in 1999 and Love The Lord in the Power Gold Cup of 1996.
He was afforded a guard on honour by his fellow jockeys after his ride on Vigil.
Treacy said: “I’m getting out with no regrets. I’ve met some lovely people and loved every minute.
“Leopardstown has been a lucky track for me and it’s a great way to go out here today, with all my family here.
“Danoli winning the Hennessy Gold Cup was a great day and the roar after we came back in was incredible.
“Those days of riding Danoli were unbelievable, I’ll never forget it. Even walking in today I had butterflies.”
He added: “I’m working for Dermot Weld now, which is great. I couldn’t have someone better to work for and it’s great to have that bit of security for the future.”
Paul Townend is expected to be out of the saddle for around 10 days.
Townend returned to action on Saturday for his first mounts since December 13, but stood himself down after the first race.
He finished fourth on Beau Mome in the Clayton Hotel Leopardstown Maiden Hurdle, but felt he was not in the right shape to continue
The Turf Club’s medical officer Dr Adrian McGoldrick said: “Paul Townend has a bone bruise on his right lower tibia which is still giving him some trouble.
“He will be out for 10 days but should be OK after that.”
As a result, Townend missed the armchair ride on Douvan in the feature Grade One Racing Post Novice Chase, with Patrick Mullins stepping in.