- Jan 1 7th Rose Bowl: California beats Ohio State 28-0
- Jan 2 1st religious service radio broadcast in US, KDKA-Pittsburgh
- Jan 2 DeYoung Museum in Golden Gate Park opens
- Jan 3 "Svoboda", Ukrainian language newspaper based in Jersey City, New Jersey, expands to daily publication (reverts to weekly in 1998)
- Jan 3 Turkey makes peace with Armenia
Diff'rent
Jan 4 Eugene O'Neill's play "Diff'rent" premieres in NYC
- Jan 6 The Iraqi Army is formed
Venizelos' Fourth Term
Jan 16 Eleftherios Venizelos becomes Prime Minister of Greece (4th time)
- Jan 18 William Archer's play "Green Goddess" premieres in NYC
- Jan 19 Costa Rica, Guatemala, Honduras & El Salvador sign Pact of Union
- Jan 20 British submarine HMS K5 (which was unusually equipped with steam turbines) sinks with 57 crew during exercises in the Bay of Biscay
- Jan 20 Dagestan ASSR forms in RSFSR
- Jan 20 Mountain Autonomous Republic established in RSFSR
- Jan 20 Republic of Turkey declared out of remnants of the Ottoman Empire
Agatha Christie's First Novel
Jan 21 British crime writer Agatha Christie publishes her first novel "The Mysterious Affair at Styles" introducing the character Hercule Poirot
Italian Communist Party
Jan 21 Italian Communist Party founded at Livorno by Amadeo Bordiga and Antonio Gramsci
- Jan 24 Paris Conference on reparations is held
Theater Premiere
Jan 25 Karel Čapek's play "R.U.R." premieres in Prague, introduces the word "robot"
- Jan 26 Toronto NHL center Corb Denneny scores 6 goals to lead St. Patricks to a 10-3 win over Hamilton Tigers in Toronto
- Jan 29 Great Olympic Blowdown: Hurricane force winds hit US Pacific Northwest states of Washington and Oregon [1]
- Jan 30 French rapist-murderer Henri-Desire Landru sentenced to death
Authors
Dictators
Explorers
Outlaws
Queens
Spies