Julius Reinhard Oppel (Grünberg, Hesse 1878-Leipzig, 1941) was a German composer. He studied at the Hoch Conservatory in Frankfurt 1903-1909, was briefly an organist in Bonn, then from 1911 professor of composition at the Kiel Conservatory of Music, and from 1928 professor of music theory at the Leipzig Conservatory. Oppel was a student, correspondent, and friend of Heinrich Schenker, the famous Viennese Jewish music theorist, and made efforts to disseminate Schenkerian theory while a professor at Leipzig.