Sir Cosmo Edmund Duff Gordon, 5th Baronet (July 22, 1862 - April 20, 1931), the son of the Hon. Cosmo Lewis Duff-Gordon and the former Anna Maria Antrobus, was a prominent Scottish landowner and sportsman. He was particularly noted as a fencer, representing Great Britain at the 1906 and 1908 Olympics. Co-founder of the London Fencing League, he was a member of the Bath Club and the Royal Automobile Club. He was a sheriff and magistrate in his native Kincardineshire, near Aberdeen, where his ancestral country estate Maryculter was located.

Duff Gordon was the fifth baronet of Halkin, his title stemming from a royal licence conferred on his great uncle in 1813 in recognition of his aid to the Crown during the Peninsular War. In 1772 his family founded the Duff Gordon sherry bodega in Spain, which still produces high quality fortified wines.

In 1900, Duff Gordon married the famous London fashion designer "Madame Lucile" (nee Lucy Christiana Sutherland/Mrs. James Stuart Wallace). Her marriage to Duff Gordon was her second. For more information on Lucile, see under Lucy, Lady Duff-Gordon.

Cosmo Duff Gordon is best known for surviving the sinking of the RMS Titanic in 1912, along with his wife and her secretary. Rumors that the Duff Gordons bribed the crew in their lifeboat not to rescue people in the water threatened their reputations, however the British Board of Trade's Inquiry into the disaster cleared them of any wrongdoing.

He is buried at Brookwood Cemetery, near London. Cosmo Duff Gordon was portrayed by Martin Jarvis in the 1997 film Titanic.