Cosmo Duff-Gordon participant of 1906 Intercalated Games
As a sportsman, Duff-Gordon was most noted as a fencer, representing Great Britain at the 1906 Intercalated Games, winning silver in the team épée event. King Edward VII and Queen Alexandra were among distinguished spectators at one of the final bouts between Sir Cosmo and his German opponent Gustav Casmir. Duff-Gordon served on the organizing committee at the 1908 Summer Olympics, appointed by Lord Desborough, chairman of the British Olympic Association.  He took part in pistol duelling competitions and was a member of the British team demonstrating the sport in the fencing arena at the 1908 Games.  He was also a self-defence enthusiast who trained with champion Swiss wrestler Armand Cherpillod at the Bartitsu Club in London's Soho district. He was a co-founder of the London Fencing League, a member of the Bath Club and the Royal Automobile Club. He was also a sheriff and magistrate in his native Kincardineshire, near Aberdeen, where his ancestral country estate Maryculter was located.