The title of champion, or leading, sire of racehorses in Great Britain and Ireland is awarded to the stallion whose offspring have won the most prize money in Britain and Ireland during the flat racing season. The current (2022) champion is Dubawi, who earned his first title after finishing runner-up multiple times.

Northern Dancer was a Thoroughbred that, in 1964, became the first Canadian-bred horse to win the Kentucky Derby. After being retired from racing, he became one of the most successful sires of the 20th century. He is considered a Canadian icon and was inducted into the Canadian Sports Hall of Fame in 1965. Induction into the Racing Hall of Fame in both Canada and the United States followed in 1976. As a competitor, The Blood-Horse ranked him as one of the top 100 U.S. Thoroughbred racehorses of the 20th century. As a sire of sires, his influence on the breed is still felt worldwide.