The Partisan 9th Corps (Slovene: IX Korpus), was a formation of the Yugoslav Partisans during World War II. It consisted of division and brigade-size units, and operated in the Italian-annexed Province of Ljubljana, in Yugoslav territories under German civil administration, the Independent State of Croatia and northeastern Italy during World War II.
The corps took part in many operations against Germans and Italians forces prior to the surrender of Italy on 8 September 1943. One of the most significant was the German Operation Adler.
After a decision of Palmiro Togliatti, all communist units (named Garibaldini after Giuseppe Garibaldi) operating in territories reclaimed by Yugoslavians were to be incorporated into NOVJ (the Popular Yugoslavian Army of Liberation), and wrote personally the content of the order of the day to be adopted by communist partisans.