After an unsuccessful UK campaign, Storm Boy will return to Australia.

Only a few days after finishing out of the placings at Royal Ascot, the decision has been made to retire Magic Millions winner Storm Boy.

Lameness was detected after the colt's tenth placing in the Group 1 Queen Elizabeth Stakes (1207m) on Saturday so the three-year-old will come back to Australia and stand at Coolmore with the service fee set at $16,500.

Bought for $460,000 at the 2023 Gold Coast Magic Millions Yearling sale by a partnership including Gai Waterhouse and Adrian Bott, Storm Boy amassed more than $3.5 million in prizemoney in five wins and two placings in 12 starts.

Setting four-straight victories to begin his career with the training pair, the son of Justify left little to doubt his quality which was highlighted by winning the 2024 Magic Millions 2yo Classic (1200m) before following up in the Group 2 Skyline Stakes (1200m).

A third placing in the Group 1 Golden Slipper Stakes (1200m) behind Lady of Camelot earned a Racing and Sports rating of 115, one pound shy of his then career best of 116 in the Magic Millions.

In his first run as a three-year-old in August 2024, Storm Boy notched 118 when winning the Group 3 San Domenico Stakes (1100m) at Rosehill.

His ultimate career peak of 119 came in defeat when finishing eighth in the Group 1 The Everest (1200m) in a tough effort with Bella Nipotina the victor.

"He was jaw-dropping, much like his sire Justify," Coolmore Australia's Tom Magnier said.

'He won five of his first seven starts in a really dominating fashion and was unlucky not to include a Golden Slipper in that tally.

"We took Storm Boy to Europe with the plan of winning the QE II Jubilee Stakes at Royal Ascot but unfortunately we haven't been able to give him the ideal prep.

"We felt we were getting back to where we needed to be with him, but he was found to be quite lame since returning to Ballydoyle on Saturday."

Storm Boy will stand at Coolmore along with star recruit City Of Troy – also by Justify – who has a full booking at stud for the new season.