- May 1 John Walker, English inventor and chemist who invented the friction match, dies at 77
- May 2 Eliza Courtney, English illegitimate daughter of Charles Grey and Georgiana Cavendish, Duchess of Devonshire, dies at 67
- May 4 Joseph Diez Gergonne, French mathematician, dies at 87
- May 5 Peter Gustav Lejeune Dirichlet, German mathematician (number theory), dies at 53
Alexander von Humboldt (1769-1859)
May 6 German naturalist and explorer (Kosmos), dies at 89
Assassination
Car Crash
Hanging
Killed in Action
Plane Crash
Poisoning