Blacklock (1814 – 24 February 1831) was a British Thoroughbred racehorse who won seventeen of his twenty-three races. As a two-year-old in 1816 he was undefeated in three starts. In his first race as a three-year-old he finished second in the St. Leger, a neck behind Ebor. He then won four races in two weeks, including the and . In 1818 he recorded several wins including two of the Great Subscription Purses at York. He won a third Great Subscription Purse in 1819, along with the York Gold Cup. After retiring from racing, Blacklock became a successful stallion and was champion sire of Great Britain in 1829, the year his son Voltaire won the Doncaster Cup. He was owned by Thomas Kirby as a two-year-old, before being purchased by Richard Watt, who owned him for the remainder of his racing ca