Racing at age two in France for his British breeder/owner, Jefferson Davis Cohn, Sir Gallahad earned victory in three of his five starts but was overshadowed by the 1922 Champion colt, Epinard.

At age three, he won four races, most notably the French 2,000 Guineas (Poule d'Essai des Poulains).

Sir Gallahad was retired after his four-year-old season to stand at stud at Haras du Bois-Roussel in Alençon.

In 1926, owner Jefferson Davis Cohn sold him to an American syndicate made up of Robert A. Fairbairn, William Woodward Sr., Marshall Field III, and Arthur B. Hancock.

In addition, Sir Gallahad was the U.S. Champion Broodmare Sire a record 12 times, with his daughters producing 139 stakes winners including two Hall of Famer members: Challedon and Gallorette.