Adagio for Strings is a work by Samuel Barber, arguably his best known, arranged for string orchestra from the second movement of his String Quartet, Op. 11.
Barber finished the arrangement in 1936, the same year that he wrote the quartet. It was performed for the first time on November 5, 1938, by Arturo Toscanini conducting the NBC Symphony Orchestra in a radio broadcast from NBC Studio 8H. Toscanini also played the piece on his South American tour with the NBC Symphony in 1940.
Its reception was generally positive, with Alexander J. Morin writing that Adagio for Strings is "full of pathos and cathartic passion" and that it "rarely leaves a dry eye". The music is the setting for Barber's 1967 choral arrangement of Agnus Dei. Adagio for Strings has been featured in many TV shows and movies.