Sickle (8 February 1924 – 26 December 1943) was a British-bred thoroughbred racehorse who was later exported to the US where he was twice the leading sire in North America.

The colt met with some success in racing, winning three of his ten starts and notably finishing third in a field of 23 in the 2,000 Guineas Stakes in 1927.

His progeny includes: Sickle's bloodline legacy came through his son Unbreakable who sired the 1945 Preakness Stakes winner and the 1947 American Champion Sprint Horse, Polynesian.

Polynesian in turn sired the US Racing Hall of Fame inductee Native Dancer who was rated No.7 in the Blood-Horse Magazine List of the Top 100 US Racehorses of the 20th Century.

Because of Polynesian, Sickle's sireline includes Sea Bird, the 1965 Epsom Derby and Prix de l'Arc de Triomphe winner whose Timeform rating is the second highest ever awarded in flat racing, and the very influential Mr. Prospector, a two-time leading sire in North America and nine-time leading broodmare sire in North America.