The Peter Young Stakes, registered as the St George Stakes, is a Melbourne Racing Club Group 2 Thoroughbred horse race held under weight for age conditions over a distance of 1800 metres at Caulfield racecourse, Melbourne, Australia in late February. Total prize money is A$300,000.

Tranquil Star was one of the hardiest and best performed Australian-bred Thoroughbred race-mares. She is the only mare to have won the double of the Caulfield Stakes, now known as the Yalumba Stakes, and the Cox Plate, which is the most prestigious weight-for-age (wfa) race in Australia. Tranquil Star had 111 starts and won over distances ranging from 5 furlongs to 14 furlongs. She was later inducted into the Australian Racing Hall of Fame.