Sir Cosmo Edmund Duff-Gordon, 5th Baronet, DL (22 July 1862 – 20 April 1931) was a prominent Englishman and sportsman who owned land in Scotland, best known for the controversy surrounding his escape from the sinking of the RMS Titanic.

In 1900, Duff-Gordon married the celebrated London fashion designer "Madame Lucile" (née Lucy Christiana Sutherland, then Mrs. James Stuart Wallace).

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.

[3] 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.

He was not "on trial" but received much press criticism which claimed that he bribed the sailor in charge of the lifeboat with a £5 note not to return to rescue people struggling in the water.

Sir Cosmo and Lady Duff-Gordon were portrayed by the actors Martin Jarvis and Rosalind Ayres, themselves a married couple, in the 1997 film Titanic.

In 2012 a box of documents and letters concerning the Titanic sinking belonging to the Duff-Gordons was rediscovered at the London office of Veale Wasbrough Vizards, the legal firm that merged with Tweedies, who represented the couple.

"[15] Despite the official vindication by the Board of Trade inquiry, public suspicion that the Duff-Gordons had acted selfishly tainted the couple for the remainder of their lives.