Snow Fairy will head to the breeding sheds in Ireland after Ed Dunlop called time on the brilliant mare's career.
The six-times Group One winner, who landed last year's Irish Champion Stakes and the 2010 Irish Oaks, suffered a tendon injury during a workout on Tuesday morning.
Dunlop said: "It is with much sadness that a decision was made this morning to retire Snow Fairy. Unfortunately, after a routine piece of fast work, she was found to have re-injured her near fore tendon, which has caused her problems in the last two years.
"I would like to take this opportunity to personally thank Mrs (Cristina) Patino for all she has done, she has been the most wonderful owner of a truly amazing horse.
"Most owners would have retired her a lot sooner than she did and if this had been the case she would not have won the Irish Champion Stakes last year, which was without doubt her greatest performance.
"I would also like to thank all of my staff who have looked after her, ridden her and travelled her around the world. She remains the only international horse to have won two Group Ones in Japan.
"Snow Fairy will return to Ireland, where I hope she will have a fantastic life as a broodmare."
Patino's racing manager Patrick Cooper said: "We've had an unbelievable roll. It's come to an end, but that's the way it happens. We've had some fun along the way.
"She will go to Elusive Pimpernel. He is Mrs Patino's horse and was a very good two-year-old a few seasons back. She will visit him. That will be next year.
"She will just be let down. She will stay with Ed for a little while then she will come down to Islanmore Stud in Limerick."