Treaty of Interest
May 14 Great Britain signs treaty with Emperor Menelik II of Abyssinia

Menelik II
- May 15 The Greek army retreats with heavy losses in the Greco-Turkish War.
Event of Interest
May 15 The Scientific-Humanitarian Committee is founded in Berlin by Magnus Hirschfeld, the first-ever LGBT rights organization

Magnus Hirschfeld
Event of Interest
May 17 The first successful submarine that can run submerged for any considerable distance and combines electric and gasoline engines is launched in the USA by its designer John Philip Holland

John Philip Holland
Historic Publication
May 18 "Dracula" by Irish author Bram Stoker is published by Archibald Constable and Company in London

Bram Stoker
Event of Interest
May 18 Herbert Henry Dow founds Dow Chemical in Midland, Michigan

Herbert Henry Dow
Event of Interest
May 19 Oscar Wilde is released from Reading Gaol

Oscar Wilde
- May 20 British Open Men's Golf, Royal Liverpool GC: English amateur Harold Hilton wins 2nd Open title by 1 stroke from Scot James Braid
- May 21 Yerkes Observatory 40" (1m) refractor used for 1st time
- May 22 The Blackwall Tunnel, London, under the River Thames is officially opened
- May 29 31st Belmont: Joe Scherrer aboard Scottish Chieftain wins in 2:23.25