- Feb 11 Vatican City (world's smallest country) made an enclave of Rome
- Feb 14 St Valentine's Day Massacre in Chicago, 7 gangsters killed, allegedly on Al Capone's orders
- Jun 3 Chile and Peru sign the Treaty of Lima, finally resolving their border dispute from the War of the Pacific (1879–83). Chile keeps Arica and Peru regains Tacna.
- Jun 7 Vatican City becomes a sovereign state
- Jun 25 US President Herbert Hoover authorizes building of Boulder Dam (Hoover Dam)
- Jun 27 1st color TV demo, performed by Bell Laboratories in NYC
- Oct 24 "Black Thursday", start of stock market crash, Dow Jones down 12.8%
- Oct 29 "Black Tuesday" Wall Street Stock Market crashes triggering the "Great Depression"
- Dec 2 First skull of Peking man found, 50 km out of Peking at Tsjoe Koe Tien
- Jan 3 Bradman scores 112 v England at MCG - his 1st Test century
- Apr 16 NY Yankees become 1st team to wear uniform numbers
- Aug 7 NY Yankees slugger Babe Ruth ties MLB record by hitting grand slams in consecutive games for the second time in 13-1 win v Philadelphia A's
- Aug 11 Babe Ruth becomes 1st professional baseball player to hit 500 homers (off Willis Hudlin of Cleveland Indians)
Women are considered "Persons" under Canadian law
On October 18, 1929