The Symphony for Organ No. 6 (Symphonie VI pour orgue) in G minor, Op. 42, No. 2, is an organ symphony by Charles-Marie Widor. Completed in 1878, the composer premiered it at the Palais du Trocadéro as part of the Paris World Exhibition. It was first published by Hamelle in 1879, together with the famous Symphony for Organ No. 5.