Otto Erich Deutsch (5 September 1883 - 23 November 1967) was an Austrian musicologist. He is known for compiling the first comprehensive catalogue of Franz Schubert's compositions, first published in 1951 in English, with a revised edition published in 1978 in German. It is from this catalogue that the D numbers used to identify Schubert's works derive.
Following his studies of art history and literature in Vienna and Graz, he worked as a lecturer at the Department of Art History of the University of Vienna. His specialization was the Biedermeier period, which led naturally to his interest in Schubert, whose life took place during this cultural era. His scholarly career was interrupted by World War I when he served in the Austrian Army. Following the war Deutsch worked for a time as a bookseller. He also shifted his scholarly interests to historical musicology, eventually becoming music librarian, working in the archives of Anthony van Hoboken. In 1938, when Austria was taken over by Nazi Germany in the Anschluss, Deutsch decided to flee the country, as he was of Jewish origin. He lived in Cambridge, England, from 1939 to 1951, returning to Vienna after the war.
According to Jones, Deutsch's work was based on "an abiding belief that historical documents and iconographic evidence constituted the essential ingredients of biographical exposition." Hence, Deutsch composed "documentary biographies" of Schubert, Mozart and Handel; in them, the texts of the old documents are placed in chronological order, strung together with narration and commentary by Deutsch. In these biographies, Deutsch lets the documents speak for themselves, with his supplementary remarks providing clarifications, corrections, and context.
He was awarded the Austrian Cross of Honour for Science and Art, 1st class in 1959.