Hillstar (foaled 22 February 2010) is a British Thoroughbred racehorse and sire. After winning one minor race as juvenile he improved to become one of the best middle-distance colts of his generation in Britain, winning the King Edward VII Stakes as well as finishing third in the King George VI and Queen Elizabeth Stakes. As a four-year-old he won the Legacy Cup before recording his biggest success in the Canadian International Stakes. He raced without success in 2015 before being retired to become a breeding stallion in Ireland.