Frederick Cunliffe-Owen was educated at Lancing College and the University of Lausanne. He joined the diplomatic service and spent time in Egypt and Japan. In 1877 he married Emma Pauline de Couvreu de Deckersberg. They were divorced in Switzerland in 1887.
In 1885 Cunliffe-Owen moved to New York City with his second wife, Marguerite de Godart, comtesse de Planty et de Sourdis, who was known as Countess Marguerite Cunliffe-Owen. He wrote for the New York Tribune, becoming first the paper's foreign editor and later its society editor. Using the pseudonym "Marquise de Fontenoy", Cunliffe-Owen wrote syndicated feature articles about European aristocratic and court society. He also wrote a series called "An Ex-Attaché's Letters" about European diplomatic and political affairs and wrote editorials on these subjects for the New York Times. In 1916 he was sued by Rudolph de Landas Berghes for libel, after writing to the Bishop of Pennsylvania to warn him "against giving any countenance whatsoever to the soi-disant 'Prince de Berghes' ".
Cunliffe-Owen received numerous honours including being named a Knight of the Order of Orange-Nassau in 1908 and Commander of the Order of the British Empire and Knight Commander of the Order of the White Eagle (Serbia) in 1920.