Voltaire was a British Thoroughbred racehorse. He won five of his six races, including the Doncaster Gold Cup in 1828. After retiring from racing he became a successful stallion, siring St. Leger winner Charles the Twelfth and Voltigeur, who won both The Derby and the St. Leger. He was bred and owned by Robert Stephenson, before being sold to William Vane, Marquess of Cleveland, whom he raced for as a three-year-old.

The Doncaster Cup is a Group 2 flat horse race in Great Britain open to horses aged three years or older. It is run at Doncaster over a distance of 2 miles 1 furlong and 197 yards, and it is scheduled to take place each year in September.