Michael Langdon CBE (born Frank Birtles; 12 November 1920 – 12 March 1991) was a British bass opera singer. Despite little musical training, he joined the chorus of the Covent Garden Opera Company after the Second World War, graduating to minor and then major solo roles. Covent Garden remained his base throughout his career, but he sang as a guest in opera houses in Continental Europe and the Americas.
Langdon was particularly noted for his performance as Baron Ochs in Richard Strauss's Der Rosenkavalier, which he sang more than a hundred times in opera houses from London to Paris, Buenos Aires, New York and Vienna. Although known for playing comic roles like Ochs, he could be menacing when required, as in the role of Claggart in Benjamin Britten's Billy Budd or the villains in Wagner's Der Ring Des Nibelungen.
Langdon announced his retirement from the stage in 1977, and became the founding director of the National Opera Studio, training the next generation of singers for the operatic stage.