- May 10 James Gordon Bennett Jr., American publisher (thought to have inspired the phrase "Gordon Bennett"), born in New York City (d. 1918)
- May 11 Ernst von Possart, German actor and theatre director (Bayerische Hoftheater), born in Berlin, Germany (d. 1921)
- May 14 Sir Squire Bancroft [Butterfield], British actor and manager known for creating 'drawing-room comedy' (Haymarket), born in Rotherhithe, London (d. 1926)
- May 15 Giovanni Bolzoni, Italian violinist and composer, born in Parma, Duchy of Parma (now Italy) (d. 1919)
- May 20 Sara Louisa Oberholtz, American economist and social reformer (children's school savings banks), born in Uwchlan Township, Pennsylvania (d. 1930)
- May 21 Joseph Parry, Welsh composer and musician, born in Merthyr Tydfil, Wales (d. 1903)
- May 22 Catulle Mendès, French poet, born in Bordeaux, France (d. 1909)
- May 24 Charles Napier Hemy, British painter, born in Newcastle, England (d. 1917)
- May 24 Tito Mattei, Italian pianist and composer, born in Campobasso, Kingdom of Naples (d. 1914)
- May 28 Giovanni Sgambati, Italian pianist and composer, born in Rome, Papal States (d. 1914)
- May 29 Sylvester Magee, last living American slave and oldest person who ever lived, born in North Carolina (d. 1971)
20-29
30-39
40-49
50-59
80-89
Over 90