String Quartet No. 12 may refer to:
String Quartet No. 12 (Beethoven) by Ludwig van Beethoven String Quartet No. 12 (Dvořák), American, by Antonín Dvořák String Quartet No. 12 (Hill) by Alfred Hill String Quartet No. 12 (Maconchy) by Elizabeth Maconchy String Quartet No. 12 (Milhaud), Op. 252, by Darius Milhaud String Quartet No. 12 (Mozart) by Wolfgang Amadeus Mozart String Quartet No. 12 (Schubert) by Franz Schubert String Quartet No. 12 (Shostakovich) by Dmitri Shostakovich String Quartet No. 12 (Spohr) by Louis Spohr String Quartet No. 12 (Villa-Lobos) by Heitor Villa-Lobos