- Dec 1 Gasoline rationed in US
- Dec 1 The Beveridge Report is published by the British government unveiling plans for a post-war welfare state
- Dec 1 With WWII travel restrictions in mind, MLB owners decide to restrict travel to a 3-trip schedule rather than customary 4; Spring training in 1943 limited to locations north of Potomac or Ohio rivers and east of the Mississippi
Event of Interest
Dec 2 World’s 1st self-sustaining nuclear chain reaction occurs in Chicago Pile-1 (world's 1st nuclear reactor) at the University of Chicago, overseen by Enrico Fermi

Enrico Fermi

Leó Szilárd
- Dec 4 First US citizenship granted to an alien on foreign soil (James Hoey)

Franklin D. Roosevelt
- Dec 4 US bombers strike Italian mainland for first time in WW II
- Dec 4 Holocaust: In Warsaw, Zofia Kossak-Szczucka and Wanda Filipowicz set up the Żegota organization
- Dec 5 CFL Grey Cup, Varsity Stadium, Toronto: Toronto RCAF Hurricanes beat Winnipeg RCAF Bombers, 8-5
- Dec 5 Seyss-Inquart orders students in nazi-Germany to work
- Dec 5 West Indies chocolate/coffee drop above Netherland
Event of Interest
Dec 6 Queen Wilhelmina announces Dutch Commonwealth

Wilhelmina of the Netherlands
Appointment of Interest
Dec 10 Adolf Hitler names Anton Mussert "leader of the Dutch people"

Adolf Hitler
- Dec 10 North Africa: 5th German panzer army forms under col-gen von Arnim
Event of Interest
Dec 10 An early report the Holocaust prepared by the Polish government-in-exile, using information obtained by Witold Pilecki, is addressed to UN member states

Witold Pilecki
- Dec 11 Australian Dutch guerrilla troops evacuated to Timor near Australia
- Dec 12 German offensive in South Western Stalingrad
- Dec 12 A fire in a hostel in St. John's, Newfoundland, kills 100 people
- Dec 13 Seyss-Inquart allows Dutch Nazi Anton Mussert to call himself Leader
- Dec 13 National Football League Championship, Griffith Stadium, Washington, D.C.: Washington Redskins upset Chicago Bears, 14-6
- Dec 15 Massachusetts issues 1st US vehicular license plate tabs
- Dec 16 Hitler orders combat against partisans in Russia & Balkan
- Dec 17 Allies in London sentence German war criminals
- Dec 19 Robert Stroud "Birdman of Alcatraz" is transferred to Alcatraz Federal Penitentiary
- Dec 20 1st Japanese bombing of Calcutta
- Dec 21 US Supreme court declares Nevada separation legal
- Dec 22 World War II: Adolf Hitler signs the order to develop the V-2 rocket as a weapon
- Dec 23 Allies air attack on Den Helder, Netherlands
- Dec 24 First powered flight of V-1 'buzz bomb', Peenemunde, Germany
- Dec 24 Red army occupies German airports at Tasjinskaja & Morozowsk
- Dec 25 Admiral Dalans murderer of Bosinier de la Chapelle, sentenced to death
- Dec 25 British Colonel S W Bailey reaches Mihailovics headquarter
- Dec 25 Soviet artillery and tank battle on German armies at Stalingrad
- Dec 27 1st Japanese women camp (Ambarawa) goes into use
- Dec 27 5th NFL All Star Game, Shribe Park, Philadelphia: NFL All-Stars beat Washington Redskins, 17-14
- Dec 27 The Union of Pioneers of Yugoslavia is founded.
- Dec 28 Oberkommando Wehrmacht orders strategist flight out of Kaukasus
- Dec 28 Robert Sullivan becomes 1st pilot to fly Atlantic 100 times
- Dec 31 Battle of the Barents Sea between British Navy and German Kriegsmarine off North Cape, Norway