- September 3: Britain declares war on Germany
- September 4: Alan Turing reports for duty at the Government Code & Cipher School in Bletchley Park.
- December 22: Ma Rainey dies of a heart attack.
- Memphis Minnie writes a tribute song to Ma Rainey.
- May 15: Jackie Shane is born.
- October 7: Althea Garrison is born.
- October 31: Craig Rodwell is born.
- Willem Arondeus begins an underground periodical as part of the Dutch Resistance.
- Allied forces invade Sicily, storing munitions in the Addaura Cave. Some of the stored ammunition explodes, exposing previously undiscovered prehistoric rock art.
- Willem Arondeus joins force with another underground publication in order to increase their circulation.
- March 27: Willem Arondeus leads the bombing of the Amsterdam Public Records Office, in order to hinder Nazi efforts to root out Jews in the area.
- July 1: Willem Arondeus is executed by Nazis. His last words are: “Let it be known that homosexuals are not cowards.”
- September 2: Carol Byron is born.
- Alan Turing begins working on the Automatic Computing Engine (ACE).
- Christine Jorgensen — still living as a man — graduates high school and joins the Army — serving during the end of World War II.
- Willem Arondeus is awarded a posthumous medal and buried at Erebegraafplaats Bloemendaal.
- August 24: Marsha P. Johnson is born.