String Quartet in D major may refer to: No. 4 of the String Quartets, Op. 20 (Haydn) No. 6 of the String Quartets, Op. 33 (Haydn) No. 6 of the String Quartets, Op. 50 (Haydn) No. 5 of the String Quartets, Op. 64 (Haydn) No. 5 of the String Quartets, Op. 76 (Haydn) String Quartet No. 2 (Mozart) String Quartet No. 20 (Mozart) String Quartet No. 21 (Mozart) String Quartet No. 3 (Beethoven) String Quartet No. 6 (Schubert) String Quartet No. 7 (Schubert) String Quartet No. 3 (Mendelssohn) String Quartet (Franck) String Quartet No. 2 (Borodin) String Quartet No. 1 (Tchaikovsky) String Quartet No. 3 (Dvořák) String Quartet No. 4 (Piston) String Quartet No. 4 (Shostakovich) String Quartet in D major (Britten) (1931) String Quartet No. 1 (Britten)