Hennessy String Quartet no. 1, Op. 46

String Quartet no. 1, Op. 46 is a composition in four sections by Swan Hennessy. It was first published in 1913 by E. Demets and dedicated to Carl Heffner. The Vivacissimo section of the last movement is based on piece No. 902 from The Complete Collection of Irish Music by George Petrie, as is 'Molly on the Shore by Grainger', published in 1911.