Julius Deutsch (February 2, 1884, Lackenbach, Austria-Hungary – January 17, 1968, Vienna, Austria) was a politician of the Social Democratic Workers' Party of Austria, member of Parliament between 1920 and 1933, and co-founder and leader of the Social Democrat militia Republikanischer Schutzbund ("Republican Defense Association").

Julius Deutsch founded the Schutzbund in 1923 as an answer to the paramilitary organization Heimwehr ("Home Guard"), which was ideologically related to the Christian Social Party.

After the defeat of the Republican Guard during the Austrian Civil War of 1934 and the following ban on the Social Democrats, he fled to the city of Brno in Czechoslovakia.

After the occupation of France by National Socialist Germany, Deutsch, who was of Jewish descent, had to emigrate again, this time to the United States of America.

Julius Deutsch was also an uncle of Karl Wolfgang Deutsch, a renowned German-American social and political scientist; the grandfather of Canadian economist Gerald Karl Helleiner;[3] and great-grandfather of Canadian political scientist Eric Helleiner.