- Dec 1 1st skywriting over US - "Hello USA"-by Capt Turner, RAF
Historic Event
Dec 1 Polish state Chief Marshal Józef Piłsudski resigns
- Dec 2 CFL Grey Cup, Richardson Stadium, Kingston: Queen's University win first of 3 straight titles; defeat Edmonton Elks, 13-1
- Dec 4 Lucille Atcherson, becomes first woman legation sect-US foreign service
- Dec 6 1st constitution of Irish Free State comes into operation
- Dec 6 1st electric power line commercial carrier in US, Utica, NY
- Dec 9 1st Australasian Championships Women's Tennis, Sydney: Margaret Molesworth wins inaugural title; beats fellow Australian Esna Boyd 6-3, 10-8
- Dec 9 Australasian Championships Men's Tennis, Sydney: James Anderson wins 1st of 3 Australasian titles; beats fellow Australian Gerald Patterson 6-0, 3-6, 3-6, 6-3, 6-2
- Dec 9 Gabriel Narutowicz elected Polish president
- Dec 10 1st National Football League Championship: undefeated Canton Bulldogs (10-0-2) named inaugural champions
Nobel Prize
Dec 10 Nobel prizes awarded to Danish physicist Niels Bohr for his work on the structure of atoms, Francis William Aston for Chemistry and a Peace Prize to Fridtjof Nansen for his work on behalf of displaced victims of World War I at a ceremony in Copenhagen
- Dec 10 Pete Henry makes longest known NFL drop-kicked field goal, 45 yards
- Dec 13 Charles Ebbets proposes putting numbers on players' sleeves or caps
- Dec 15 IVVV (association) peace congress on war forms in Hague
- Dec 16 Mutual Association of Eastern Colored Baseball Clubs formally organizes
- Dec 16 NSW all out for 786 against South Australia Cricket
- Dec 17 Last British troops leave Irish Free State
- Dec 19 Theresa Vaughn, 24, confesses in court in Sheffield, England, to being married 61 times over 5 years in 50 cities in three countries
- Dec 20 14 republics form Union of Soviet Socialistic Republics (USSR)
- Dec 20 Polish parliament selects Stanislaw Wojcieckowski as president
- Dec 22 Belgian parliament rejects Dutch university in Ghent
- Dec 23 BBC Radio began daily newscasts
- Dec 24 BBC broadcasts first British radio play "The Truth about Father Christmas"
- Dec 24 London Coloseum opens
- Dec 29 Dutch Constitution proclaimed
- Dec 29 Revised Netherlands Law proclaims suffrage
Soviet Union Founded
Dec 30 Creation of the USSR formally proclaimed in Moscow from the Bolshoi Theatre, Soviet Union organized as a federation of RSFSR, Ukrainian SSR, Belorussian SSR and Transcaucasian SSR
