- January 6: The Labor Socialist Party of Greece (which later became the Communist Party of Greece) hold its first open meeting in Athens.
- January 7: The first Greek units land in Odessa, Russia, as part of the Ukraine Expedition, in the Allies' effort to stem the tide of Bolshevism.
- January 17: Greek forces battle Bolsheviks at Kherson during the Ukraine Expedition.
- February 8: Greek forces battle Bolsheviks at Vaslinovo and Berezovka during the Ukraine Expedition.
- March 5: Anarchy prevails in Smyrna where armed gangs roam unmolested.
- March 6: Greek forces battle Bolsheviks at Odessa during the Ukraine Expedition.
- March 19: Greek forces begin the evacuation of Odessa during the Ukraine Expedition.
- March 29: The last of the Greek forces cross the Dniester River into Bessarabia, ending the Ukraine Expedition.
- May 15: The Greek Army lands in Smyrna, Asia Minor.
- May 18: The Greek Army enters Cesme and Alatsata.
- May 19: The second phase of the Pontian genocide begins as Mustafa Kemal Pasha lands in Samsun.
- May 25: The Greek Army occupies Magnesia, Asia Minor.
- May 27: The Greek Army occupies Aydini, Asia Minor.
- May 29: The Greek Army enters Ayvali.
- November 17: King Alexander marries Aspasia Manou - a commoner - in secrecy, in Athens.
- November 27: The Treaty of Neuilly is signed between Bulgaria and the Allies. Thrace is ceded to Greece.
- Kleanthis Maropoulos, footballer
- Adamantios Androutsopoulos, politician
- Nikolaos Makarezos, member of the military junta that governed Greece (1967 - 1973)
- Ilia Livikou, actress
- Date Unknown: Spiridon Lampros, educator, Prime Minister