Paul Stefan, born Paul Stefan Grünfeld (25 November 1879, Brno - 12 November 1943, New York City) was an Austrian music historian and critic.
Born into an assimilated Jewish family, Paul Stefan came to live in Vienna in 1898. He attended courses in law, philosophy and art history at the University of Vienna, before studying music theory with Hermann Graedener and possibly composition under Arnold Schoenberg. From 1922 to 1937 he edited the Austrian music journal Musikblätter des Anbruch (entitled simply Anbruch from 1929).
Gustav Mahler; eine studie über persönlichkeit und werk, Münich: R. Piper & Co., 1910. Translated to English as Gustav Mahler: a study of his personality and work, 1913.