- Jan 1 US & 25 other countries sign a united declaration against the Axis
- Jan 1 28th Rose Bowl: #12 Oregon State beats #2 Duke, 20-16 (played in North Carolina due to Japanese threat)
- Jan 1 8th Sugar Bowl: #6 Fordham beats #7 Missouri, 2-0
- Jan 1 8th Orange Bowl: #14 Georgia beats TCU, 40-26
- Jan 2 World War II: the 28 nations at war with Axis powers pledge to make no separate peace deals
- Jan 2 German troops in Bardia surrender
- Jan 2 Japanese troops occupy Manila, Philippines
- Jan 2 The United States Navy opens a blimp base at Lakehurst, New Jersey
- Jan 3 American-British-Dutch-Australian (ABDA) Command forms
- Jan 4 NFL Pro Bowl: Chicago Bears beats NFL All-Stars 35-24
- Jan 4 Premier Churchill & General Marshall fly to Florida
- Jan 4 Rogers Hornsby is 14th player selected to the Hall of Fame
- Jan 5 55 German tanks reach North-Africa
- Jan 6 Bob Feller, enlists in Navy & reports for duty to Norfolk Virginia
- Jan 6 Pan American Airlines becomes the first commercial airline to schedule a flight around the world ("Pacific Clipper").
- Jan 7 WW II siege of Bataan starts
- Jan 8 British Air Marshal Richard Peirse replaced as Air Officer Commanding-in-Chief Bomber Command
Boxing Title Fight
- Jan 9 US Joint Chiefs of Staff created
- Jan 10 Japan invades North Celebes, Dutch East Indies
- Jan 11 -23°F (-31°C), Kingston, Rhode Island (state record)
- Jan 11 Japan conquers Kuala Lumpur, Malaya
- Jan 12 British troops reconquer Sollum
- Jan 12 Dutch troops on Tarakan surrender
- Jan 12 National War Labor Board created
- Jan 13 Allied Conference on war trials
- Jan 13 German U-boats begin harassing shipping on US east coast
Historic Invention
Jan 13 Henry Ford patents a method of constructing plastic auto bodies
Henry Ford
- Jan 13 Interallied war trial conference publishes St James Declaration
- Jan 13 World War II: First use of aircraft ejection seat by a German test pilot in a Heinkel He 280 jet fighter
- Jan 14 Japanese troops land at oil center Balikpapan in Borneo
- Jan 15 Cubs drop plans to install lights at Wrigley due to WW II
Franklin D. Roosevelt
- Jan 16 William Knudsen becomes 1st civilian appointed a general in US army
- Jan 18 Nazis arrest Frans Goedhart & Wiardi Beckman
- Jan 19 Japanese forces invade Burma
- Jan 19 Titus Brandsma arrested by German occupiers
- Jan 20 Japanese invade Burma
- Jan 20 Nazi officials hold notorious Wannsee conference in Berlin to organise the "final solution", the extermination of Europe's Jews
- Jan 21 Bronx magistrate rules all pinball machines illegal
- Jan 21 Count Basie records "One O'Clock Jump"
- Jan 21 Tito's partisans occupy Foca
- Jan 22 Sietze de Groot wins 8th Dutch 11 city skate (8:44:06)
- Jan 23 Battle of Rabaul: Japanese attack Australian air base in Rabaul, New Britain
- Jan 23 Tank battle at Adzjedabia, Africa Korp vs British 8th army
- Jan 24 Musical "Star & Garter" premieres in NYC
Event of Interest
Jan 25 Lt General Rommels African corps reaches Msus
Erwin Rommel
- Jan 26 1st US force in Europe during WW II go ashore in Northern Ireland
- Jan 26 Italian supreme command demands dismissal of German Field Marshal Erwin Rommel
- Jan 27 -19°F (-27.4°C), Netherland's coldest day since 1850
- Jan 28 Soviet troops under General Timoshenko's troops move into Ukraine
- Jan 28 German troops occupy Benghazi Libya
- Jan 28 WW II Navy flier Don Mason sends message "Sighted sub sank same"
- Jan 29 1st broadcast of Roy Plomley's "Desert Island Discs" on BBC radio
- Jan 29 German & Italian troops occupy Benghazi, Libya
- Jan 29 Peru and Ecuador sign Protocol of Rio (boundary determination)
- Jan 30 Japanese troops land on Ambon