- February 11 - Leonard Gregory Kastle, composer
- Sidney F. Lamb, American linguist, father of stratificational grammar.
- Karl Benz, German automotive pioneer
- February 11 - Italy and the Vatican sign the Lateran Treaty.
- February 11 - Eugene O'Neill's "Dynamo" premieres in New York.
- October 24 - Black Thursday, beginning of the Great Depression.
- Change of US presidency from Calvin Coolidge (1923-1929) to Herbert Hoover (1929-1933)