- May 7 The settlement of Mayagüez elevates Puerto Rico to the royal status of villa by the government of Spain
- May 15 Francis Baily observes "Baily's Beads" during annular solar eclipse
Event of Interest
May 22 Felix Mendelssohn's oratorio "St Paul" premieres in Dusseldorf
Felix Mendelssohn
- May 31 HMS Beagle anchors in Simons Bay, Cape of Good Hope