- May 3 Charles XV of Sweden-Norway is crowned king of Sweden
- May 6 San Francisco Olympic Club, 1st US athletic club forms
Historic Event
May 6 Giuseppe Garibaldi's Mille sets sail from Genoa to the Kingdom of the Two Sicilies
Presidential Convention
May 16 -18] Chicago: Republican convention selects Abraham Lincoln as candidate
- May 17 German football club TSV 1860 München is founded
- May 18 US Republican Party nominates Abraham Lincoln for president
- May 26 Giuseppe Garibaldi occupies Palermo, Italy