1941

Thailand's Prime Minister Plaek Phibunsongkhram decrees January 1 as the official start of the Thai solar calendar new year (thus the previous year that began April 1 had only 9 months).

Winston Churchill, in a worldwide broadcast, tells the United States to show its support by sending arms to the British: "Give us the tools, and we will finish the job."

Yugoslav coup d'état: An anti-Axis coup d'état in the Kingdom of Yugoslavia led by General Dušan Simović, Brigadier General Borivoje Mirković, Colonels Dragutin Savić and Stjepan Burazović, Colonel General Miodrag Lazić, Milorad Petrović and many other general officers (with British support) forces Prince Paul into exile; 17-year-old King Peter II assumes power following the coup and Simović is elected new Prime Minister of Yugoslavia.

The first Defense Bonds and Defense Savings Stamps go on sale in the United States, to help fund the greatly increased production of military equipment.

WWII: The Battle of Crete ends, as the island surrenders to invading German forces.

30 – The Holocaust: Iași pogrom – "At least 13,266" Romanian Jews are massacred by local governmental forces.

WWII: A BBC broadcast by "Colonel Britton" (Douglas Ritchie) calls on the people of occupied Europe to resist the Nazis, under the slogan "V for Victory".

German troopship Bahia Laura is sunk by British submarine HMS Trident (N52) in the North Sea; 450 are killed.

Mid-October – The first P-38E Lightning fighter is produced by Lockheed in the United States.

WWII: The United States holds peace talks with Japan.

WWII:

The United States seizes the French liner SS Normandie.