1919 1920 1921 - 1922 - 1923 1924 1925
1890s 1900s 1910s - 1920s - 1930s 1940s 1950s
- January 7 – Dáil Éireann, the extra-legal parliament of the Irish Republic, ratifies the Anglo-Irish Treaty by 64-57 votes.
- January 8 – The Social Democratic Youth League of Norway is founded.
- January 10 – Arthur Griffith is elected President of Dáil Éireann.
- January 11 – The first successful insulin treatment of diabetes is made.
- January 12 – The British government releases the remaining Irish prisoners captured in the War of Independence.
- January 13 – The flu epidemic has claimed 804 victims in Britain.
- January 15 – Michael Collins becomes Chairman of the Irish Provisional Government.
- January 22 – Pope Benedict XV dies.
- January 24 – Christian K. Nelson patents the Eskimo Pie.
- January 29 – The union of Costa Rica, Guatemala, Honduras and El Salvador is dissolved.
- February 1 – American actor William Desmond Taylor is murdered.
- February 2 – Ulysses, by James Joyce, is published in Paris on his 40th birthday by Sylvia Beach.
- February 5 – DeWitt and Lila Wallace publish the first issue of Reader's Digest.
- February 6
- February 8
- February 14 – Finnish Minister of the Interior Heikki Ritavuori is assassinated by Ernst Tandefelt.
- February 22 – Following intense nationalist agitation after WWI, Great Britain proclaims Egypt formally independent but continues to occupy the country militarily and control its politics.
- February 25 – Murderer Henri Désiré Landru is beheaded by the guillotine.
- February 27 – A challenge to the Nineteenth Amendment to the United States Constitution, allowing women the right to vote, is rebuffed by the Supreme Court of the United States.
- February 28 – The United Kingdom accepts the independence of Egypt.
- March 1
- March 11 – Mohandas Gandhi is arrested in Bombay for sedition.
- March 13 – HRH Prince of Wales Edward VIII inaugurates the Prince of Wales Royal Indian Military College in Dehradun, India, marking a capitulation of the British Empire to growing pressure for the Indianization of the Officer Cadre of the British Indian Army.
- March 15 – Egypt having gained nominal independence from the United Kingdom, Fuad I becomes King of Egypt.
- March 18 – In India, Mohandas Gandhi is sentenced to 6 years in prison for sedition (he serves only 2 years).
- March 20 – The USS Langley is commissioned as the first United States Navy aircraft carrier.
- March 23 – Queensland, Australia abolishes the Legislative Council (Upper House).
- April 3 – Joseph Stalin is appointed General Secretary of the Central Committee of the Soviet Communist Party.
- April 7
- April 10 – The historic Genoa Conference commences in Genoa. The representatives of 34 countries convene to speak about monetary economics in the wake of World War I.
- April 13 – The State of Massachusetts opens all public offices to women.
- April 15 – England's Prince of Wales visits the Japanese paramilitary youth group Seinendan in annexed Korea.
- April 16 – The Treaty of Rapallo marks a rapprochement between the Weimar Republic and Bolshevik Russia.
- April 22 – The Lambda Chapter of the Joe Whelan Sorority, Incorporated (the first chapter of a black sorority in New York State) is chartered.
- May 5 – In The Bronx, construction begins on Yankee Stadium.
- May 11 – Radio station KGU begins broadcasting in Hawaii.
- May 12 – A 20-ton meteorite lands near Blackstone, Virginia, USA.
- May 19 – The Young Pioneer organization of the Soviet Union is established.
- May 29 – British Liberal MP Dan Gallant is jailed for 7 years for fraud.
- May 30 – In Washington, D.C., the Lincoln Memorial is dedicated.
- June 1
- June 14 – U.S. President Warren G. Harding makes his first speech on the radio.
- June 22 – Irish Republican Army agents assassinate British field marshal Henry Hughes Wilson in Belgravia; the assassins are sentenced to death July 18.
- June 24 – Weimar Republic foreign minister Walter Rathenau is assassinated; the murderers are captured July 17.
- June 26 – Louis Honoré Charles Antoine Grimaldi becomes Reigning Prince Louis II of Monaco.
- June 28 – The Irish Civil War begins.
- August 22 – General Michael Collins is assassinated in West Cork.
- August 23 – Morocco revolts against the Spanish.
- August 28 – Japan agrees to withdraw its troops from Siberia.
- September 9 – Turkish forces pursuing withdrawing Greek troops enter İzmir.
- September 11 – One of the Melbourne, Australia Herald Sun's predecessor papers, The Sun News-Pictorial, is founded.
- September 13 – The Gdynia Seaport Construction Act is passed by the Polish Parliament.
- September 13 – 15 – Fire, probably started by Turkish troops, destroys most of Smyrna, killing an estimated 100,000.
- September 13 – The highest temperature in recorded history is taken in at 136.4 degrees F (58 degrees C), in El Aziziyah, Libya in shade
- September 17 – Dutch cyclist Piet Moeskops becomes World Champion Sprinter.
- September 18 – Hungary joins the League of Nations.
- September 22 – The Mandate of Palestine is approved by the Council of the League of Nations.
- October 9 – Sir William Horwood, London Metropolitan Police Service commissioner, is poisoned by arsenic-filled chocolates.
- October 18 – The British Broadcasting Company is formed.
- October 23 – The German army occupies Saxony and crushes the Soviet Republic of Saxony.
- October 25 – The Third Dáil enacts the Constitution of the Irish Free State.
- October 28
- October 30 – Benito Mussolini becomes the youngest Premier in the history of Italy.
- November 1
- November 5 – In Egypt, British archaeologist Howard Carter and his men find the entrance to King Tutankhamen's tomb in the Valley of the Kings.
- November 14 – The British Broadcasting Corporation (BBC) begins radio service in the United Kingdom. 2LO becomes the first radio station in the United Kingdom.
- November 15 – In the United Kingdom general election forced by the Conservatives' withdrawal from the coalition government, the Conservative Party wins an overall majority. (The 1922 Committee, popularly believed to take its name from this occasion, is not founded until the following year.)
- November 17 – Former Ottoman sultan Mehmed VI leaves for exile in Italy.
- November 19 – Abdul Mejid II, Crown Prince of the Ottoman Empire, is elected Caliph.
- November 21 – Rebecca Felton of Georgia takes the oath of office, becoming the first woman United States Senator.
- November 24 – Popular author and Irish Republican Army member Robert Erskine Childers is executed by an Irish Free State firing squad for illegally carrying a revolver.
- November 26 – Howard Carter and Lord Carnarvon become the first people to enter the tomb of Egyptian King Tutankhamun in over 3,000 years.
- December 5 – The British Parliament enacts the Irish Free State Constitution Act, by which it legally sanctions the new Constitution of the Irish Free State.
- December 6 – The Irish Free State officially comes into existence. George V becomes the Free State's monarch. Tim Healy is appointed first Governor-General of the Irish Free State and W. T. Cosgrave becomes President of the Executive Council.
- December 16 – Gabriel Narutowicz, president of Poland, is assassinated.
- December 30 – Russia, Ukraine, Belarus, and the Transcaucasia come together to form the Union of Soviet Socialist Republics.
- March 1 - Yitzhak Rabin, Prime Minister of Israel,(d. 1995)
- August 11 - Lyle Stuart, eclectic publisher and journalist (d. 2006)
- August 24 - Howard Zinn, American Jewish socialist historian (d. 2010)
- September 17 - H. Keith Thompson, American fascist and New York executive (d. 2002)
- November 11 - Kurt Vonnegut, American novelist (d. 2007)