Wikipedia:Selected anniversaries/May 9
- 328 – Athanasius took office as Patriarch of Alexandria.
- 1915 – World War I: British forces launched the Battle of Aubers Ridge, an offensive on the Western Front, as part of the larger Second Battle of Artois.
- 1960 – The U.S. Food and Drug Administration announced that it would approve the use of Searle's Enovid, the first combined oral contraceptive pill (example pictured).
- 2018 – The Barisan Nasional coalition, which had governed Malaysia since independence in 1957, was voted out of power.