1940 is a leap year starting on Monday.
22 years of the Provisional Government of the Republic of Korea
29 years of the Republic of China
The 7th year of Kangdeok (康德) of Manchukuo
Japan, Showa 15 years
15th year of Bao Dai, Nguyen Dynasty
The 9th year of the Kangdeokje (康德帝) of Manchukuo
15th year of the Great Emperor of the Nguyen Dynasty (阮朝)
January 4 - The Japanese Government-General of Korea controls the production, distribution and screening of films due to fear of the Joseon Film Order.
January 9 - Government-General of Korea decides on new year labor mobilization plan
Japan - Promulgation of the Army Control Order and the Naval Control Order during Japanese occupation
Renamed Chang in Joseon
Founded Chosun Film Producers Association
February 14 - The Japanese Empire revised the cemetery rules and changed the reporting system to a permit system
Hattie McDaniel became the first black woman to win an Academy Award for Best Supporting Actress for her role as Mummy in Gone with the Wind.
Japan decided 18 items including coal as export control products
March 5 - Representative of the National Association, a pro-Japanese organization, departed for Tokyo, Japan to petition for the suffrage of Joseon.
March 6 - Winter War armistice.
March 21 - French cabinet Édouard Daladier resigns
March 31 - The Japanese Government-General's Office of the Japanese Government-General of the Republic of Korea Published the 37th volume of
April - Many Goguryeo murals found in Jian County, Manchuria
April 9 - World War II: Nazi Germany invades Denmark and Norway. (Operation Wezer)
April 15 - Yurim from Seoncheon, North Pyongan Province, decided as a former member of the Chang clan
April 18 - Abolition of congratulations and condolences telegram system
May - Myobeop Lotus Sutra was discovered at Jeondeungsa Temple in Ganghwa, Incheon.
May 9 - The Korean Independence Party is organized by the Korean Independence Party, the Korean National Party, the Korean Revolutionary Party, and the Hawaii Patriots Corps (Chairman Kim Gu)
World War II: British Chamberlain cabinet resigns.
World War II: German forces attack the Three Kingdoms of Benelux.
May 20 - Holocaust: Nazis create Auschwitz concentration camp.
World War II: German forces occupy Boulogne and separate British and French forces
World War II: Guderian forces cross the Somme River to secure a bridgehead
June - 23 people, including Lee Soo-young, arrested in the case of a national revival society in Nagoya, Japan
June 2 - Implementation of candy rationing system
June 7 - The Korean Language Society, announced the unification plan for foreign language notation
June 10 - World War II: Norway surrenders to Germany. (Operation Wezer)
June 11 - Started excavation of the Nakrang Tombs at the Pyongyang Museum, Goryeoji, Gangseo-gun
June 14 - World War II: German troops enter Paris.
June 23 - World War II: A visit to the French city of Paris occupied by Nazi Germany Adolf Hitler.
July - Original found in Andong, Gyeongsangbuk-do
July 1 - Government-General of Korea bans students from traveling to Manchuria and China
July 10 - Establishment of the Vichy regime in France.
July 14 - Organization of Gyeonggi-do Student Labor Corps
August 11 - The Chosun Ilbo and Dong-A Ilbo are forced to close
August 12 - World War II: German air raids on British mainland begin
August 17 - Korean Federation for National Mobilization Forces Wartime Living System
August 18 - U.S. and Canada sign a joint defense treaty
August 20 - Russian revolutionary Leon Trotsky, assassinated by an assassin in his exile in Mexico
30 August - Second Vienna Arbitration: Half of Transylvania, Romania's territory, becomes part of Hungary.
September - The Provisional Government of the Republic of Korea moves its base to Chongqing
September 7 - World War II: Nazi Germany begins the 57-day night bombing of London (Air War on the British mainland).
September 9 - Japanese colonial rule unified student uniforms in national colors
September 13 - World War II: Italy invades Egypt under Benito Mussolini (North Africa Campaign)
September 17 - The Korean Liberation Army is established by the Provisional Government of the Republic of Korea in Chongqing, Republic of China.
September 23 - 2nd �