Josef Labor (29 June 1842 – 26 April 1924) was an Austrian pianist, organist, and composer of the late Romantic era. Labor was an influential music teacher. As a friend of some key figures in Vienna, his importance was enhanced. Labor gave piano-lessons to many notable musical personalities including Alma Schindler (who married Gustav Mahler and others), Paul Wittgenstein and Arnold Schoenberg. Alma Schindler studied with Labor for 6 years, beginning when she was 14, and her diaries contain numerous references to her esteemed teacher.