Johann Baptist Joseph Maximilian Reger (19 March 1873 – 11 May 1916) was a German pianist, organist, composer, conductor, and academic teacher. He worked as a concert pianist, a musical director at the Leipzig University Church, a professor at the Royal Conservatory in Leipzig, and as a music director at the court of Duke Georg II of Saxe-Meiningen.
Reger composed first mainly Lieder, chamber music, choral music and works for piano and organ. He later turned to orchestral compositions, such as the popular Variations and Fugue on a Theme by Mozart, and to works for choir and orchestra such as Gesang der Verklärten (1903), Der 100. Psalm (1909), Der Einsiedler and the Hebbel Requiem (both 1915).