October 1: United States forces enter liberated Naples.

October 6: Americans and Japanese fight the naval Battle of Vella Lavella.

October 7: The Naples post office explosion kills 100.

October 10: The Order of Bogdan Khmelnitsky is instituted in the Soviet Union.

October 13: The new government of Italy sides with the Allies and declares war on Germany.

October 14: José P. Laurel takes the oath of office as President of the Philippines (Second Philippine Republic).

October 17: The last commerce raider hilfskreuzer Michel, is sunk off Japan by United States submarine Tarpon.

October 18: Chiang Kai-shek takes the oath of office as Chairman of the National Government of China.

October 21: Lucie Aubrac and others in her French Resistance cell liberate Raymond Aubrac from Gestapo imprisonment.

October 22: The British Royal Air Force delivers a highly destructive airstrike on the German industrial and population center of Kassel.

October 24: British Royal Navy destroyer HMS Eclipse (H08) is sunk by a mine in the Aegean Sea with the loss of 119 of the ship's company and 134 troops.

October 28: Alleged date of the Philadelphia Experiment, in which the destroyer escort USS Eldridge (DE-173) was supposed to be rendered invisible to human observers for a brief period.

October 30: The Merrie Melodies animated cartoon Falling Hare, one of the only shorts with Bugs Bunny getting out-smarted, is released in the United States. (source: Wikipedia)