- 1 May 1776 - Foundation of the Bavarian Illuminati, an Enlightenment-era secret society
- 1 May 1869 - New York Genealogical and Biographical Society elects its first woman member
- 7 May 1964 - U.S. President Lyndon B. Johnson (pictured) first makes reference to the Great Society
- 10 May 1793 - Society of Revolutionary Republican Women officially registered at the Paris Commune