Florence Foster Jenkins (born Narcissa Florence Foster; July 19, 1868 – November 26, 1944) was an American socialite and amateur soprano who became known, and mocked, for her flamboyant performance costumes and notably poor singing ability. Stephen Pile ranked her "the world's worst opera singer ... No one, before or since, has succeeded in liberating themselves quite so completely from the shackles of musical notation."

Despite – or perhaps because of – her technical incompetence, she became a prominent musical camp cult-figure in New York City during the 1920s, 1930s, and 1940s. Cole Porter, Gian Carlo Menotti, Lily Pons, Sir Thomas Beecham, and other celebrities were counted among her fans. Enrico Caruso reportedly "regarded her with affection and respect".

The poet William Meredith wrote that a Jenkins recital "was never exactly an aesthetic experience, or only to the degree that an early Christian among the lions provided aesthetic experience; it was chiefly immolatory, and Madame Jenkins was always eaten, in the end."