Julius Adler (23 January 1894 – 8 April 1945) was a German politician and member of the Communist Party of Germany.
Julius Adler was born in Neunkirchen in the Prussian Rhine Province (now Saarland), the son of a miner.
After the Nazi seizure of power, Julius Adler was arrested on 15 March 1933 in Essen, taken into "protective custody", and imprisoned at the Lichtenburg concentration camp.
After the beginning of the war in September 1939, Adler was arrested again by the Gestapo and imprisoned in the Sachsenhausen concentration camp.
Additionally during the time of the German Democratic Republic, a speedboat (183/1, type P6) of the Volksmarine of the GDR was named after Julius Adler.