- Jan 30 Hitler threatens the Jews during his speech to the German Reichstag (Parliament)
- Mar 3 Mahatma Gandhi begins a fast in Mumbai (Bombay) to protest against autocratic rule in India
- Mar 17 Sino-Japanese War (1937-1945): The Battle of Nanchang between the Kuomintang and the Japanese breaks out.
- Mar 28 Spanish Civil War ends, Madrid falls to Francisco Franco
- May 7 Germany and Italy announce an alliance known as the Rome-Berlin Axis
- May 22 Adolf Hitler & Benito Mussolini sign "Pact of Steel"
- Sep 1 World War II starts as Germany invades Poland by attacking the Free City of Danzig
- Sep 3 World War II: Britain declares war on Germany after invasion of Poland. France follows 6 hours later quickly joined by Australia, New Zealand, South Africa & Canada
- Sep 14 World’s 1st practical helicopter, the VS-300 designed by Igor Sikorsky takes (tethered) flight in Stratford, Connecticut
- Sep 28 German-Soviet Frontier Treaty is signed by Joachim von Ribbentrop and Vyacheslav Molotov; redraws German and Soviet spheres of influence in central Europe and transfers most of Lithuania to the USSR
Daily newspaper comic strip "Superman" debuts
On January 16, 1939