1923 (MCMXXIII) was a common year starting on Monday in the Gregorian calendar. The Julian calendar was made obsolete starting that year, though Eastern Orthodox churches still use the Julian Calendar.
|Centuries:||19th century – 20th century – 21st century|
|Decades:||1890s 1900s 1910s – 1920s – 1930s 1940s 1950s|
|Years:||1920 1921 1922 – 1923 – 1924 1925 1926|
- January 1 – Grouping of all UK railway companies into four larger companies
- January 10 – Lithuania seizes and annexes Memel
- January 11 – Troops from France and Belgium occupy the Ruhr area to force Germany to pay its reparation payments
- February 16 – Howard Carter unseals the burial chamber of Pharaoh Tutankhamun
- February 22 – Barcelona (Catalonia): Albert Einstein visits the city, invited by the scientist Esteban Terradas i Illa, as part of the monografics course of High Studies and Exchange organized by the Mancomunitat de Catalunya and conducted by Rafael de Campalans.
- March – Antigone by Jean Cocteau appears on a Paris stage. Settings by Pablo Picasso, music by Arthur Honegger, and costumes by Gabrielle Chanel. Antonin Artaud played the part of Tiresias.
- March 1 – USS Connecticut decommissioned
- March 2 – Time Magazine hits newsstands for the first time
- March 9 – Vladimir Lenin suffers a stroke, his third, which renders him bedridden and unable to speak; consequently he retires his position as Chairman of the Soviet government.
- April – End of Irish Civil War
- April 12 – Kandersteg International Scout Centre came into existence.
- April 23 – Ceremonial inauguration of Gdynia Seaport
- April 26 – Wedding of Prince Albert and Lady Elizabeth Bowes-Lyon in Westminster Abbey
- May 23 – Launch of Belgium's SABENA Airlines
- May 27 – Ku Klux Klan defies law requiring publication of its members
- June 9 – Military coup in Bulgaria – prime minister Aleksandar Stamboliyski is ousted (he is killed June 14)
- June 18 – Etna volcano erupts – 60.000 made homeless
- January 15 – Lee Teng-hui, 4th President of the Republic of China (d. 2020)
- January 25 – Arvid Carlsson, Swedish neuroscientist (d. 2018)
- January 31 – Norman Mailer, American writer and journalist (d. 2007)
- February 4 - Conrad Bain, Canadian-American actor (d. 2013)
- February 4 – Belisario Betancur, 26th President of Colombia (d. 2018)
- February 12 – Franco Zeffirelli, Italian film director (d. 2019)
- May 7 – Anne Baxter, American actress (d. 1985)
- May 10 – Heydar Aliyev, 3rd President of Azerbaijan (d. 2003)
- May 27 – Henry Kissinger, 56th United States Secretary of State
- May 28 – N. T. Rama Rao, Indian actor, director and politician (d. 1996)
- May 31 – Rainier III, Prince of Monaco (d. 2005)
- July 6 – Wojciech Jaruzelski, 1st President of Poland (d. 2014)
- July 11 – Richard Pipes, Polish-American academic and political expert (d. 2018)
- July 22 – Bob Dole, American politician (d. 2021)
- August 2 – Shimon Peres, 9th President of Israel (d. 2016)
- August 10 – Rhonda Fleming, American actress (d. 2020)
- October 4 – Charlton Heston, American actor and political activist (d. 2008)
- October 5 – Glynis Johns, Welsh stage and film actress, dancer, pianist and singer
- October 15 – Italo Calvino, Italian writer (d. 1985)