Margaret Ruthven Lang (November 27, 1867 – May 29, 1972) was an American composer, affiliated with the Second New England School.
Lang was also one of the first two women composers (along with Amy Beach) to have compositions performed by American symphony orchestras: Lang's Dramatic Overture, by the Boston Symphony Orchestra, 1893; Beach's Grand Mass in E-flat, 1892, by the Handel and Haydn Society; and Beach's Gaelic Symphony, 1896, by the Boston Symphony..