- May 13 Pius IX "Pio Nono" [Giovanni-Maria Mastai-Ferretti], Italian Pope (1846-78) held First Vatican Council, lost control of Papal States, born in Senigallia, Papal States (d. 1878)
- May 18 Margaret Ann Neve, British 1st recorded female Supercentenarian, who lived in three centuries, born in St. Peter Port, Guernsey (d. 1903)
- May 21 Gaspard-Gustave Coriolis, French scientist (Coriolis effect), born in Paris, France (d. 1843)
20-29
30-39
40-49
50-59
80-89
Over 90