The Sinfonia of London is a session orchestra based in London, England. Muir Mathieson, the director of music for Rank Films, founded the ensemble in 1955 specifically for the recording of film music. Over the next 25 years, the Sinfonia of London appeared on the musical credits of many British and American films.

Among the ensemble's most celebrated commercial classical recordings is its 1963 recordings with John Barbirolli conducting the Serenade for Strings of Edward Elgar and the Fantasia on a Theme of Thomas Tallis of Ralph Vaughan Williams for EMI Classics and the 1958 soundtrack album from the Alfred Hitchcock thriller Vertigo with Bernard Herrmann's score conducted by Mathieson (Mercury Records).

In February 1998, Bruce Broughton was named the orchestra's musical director.