Frank Bridge (26 February 1879 – 10 January 1941) was an English composer and violist.

Bridge was born in Brighton and studied at the Royal College of Music in London from 1899 to 1903 under Charles Villiers Stanford and others. He played the viola in a number of string quartets, most notably the English String Quartet, and conducted, sometimes deputising for Henry Wood, before devoting himself to composition, receiving the patronage of Elizabeth Sprague Coolidge. He privately tutored a number of pupils, most famously Benjamin Britten, who later championed his teacher's music and paid homage to him in the Variations on a Theme of Frank Bridge (1937), based on a theme from the second of Bridge's Three Idylls for String Quartet (1906). Bridge died in Eastbourne.

Among Bridge's works are the orchestral The Sea (1911), Oration (1930) for cello and orchestra (recorded in 1976 by Julian Lloyd Webber) and the opera The Christmas Rose (premiered 1932), but he is perhaps most highly regarded today for his chamber music. His early works are in a late-Romantic idiom, but later pieces such as the third (1926) and fourth (1937) string quartets are harmonically advanced and very distinctive, showing the influence of the Second Viennese School. His works also show harmonic influences by Maurice Ravel and especially Alexander Scriabin. One of his most characteristic harmonies is the Bridge chord, for instance C minor and D major sounding at the same time, very poignant in There Is a Willow Grows Aslant a Brook and the Piano Sonata (1922–25). He wrote this work to the memory of Ernest Farrar.

One of his most famous works is a piece for violin called Moto perpetuo (written 1900, revised 1911). Other frequently performed works are the Adagio in E for organ, Rosemary for piano, and the masterful Cello Sonata in D minor (1913–17). The Scherzetto for cello and piano was rediscovered in the library of London's Royal College of Music by the cellist Julian Lloyd Webber.