- June 22: Beginning of the Greek offensive in Anatolia.
- June 24: The Greeks defeat Turkish forces at Alasehir during the first Greek offensive of the Greco-Turkish War (1919-1922)
- July 1: The Greek Army enters Panormos and Artaki.
- July 2: Adrammytium falls to the Greek Army.
- July 9: The Greeks take Bursa during the first Greek offensive of the Greco-Turkish War (1919-1922)
- July 22: Italy renounces the Titoni-Venizelos accord and refuses to place the Dodecanese - other than Rhodes - under Greek control.
- July 24: Greek units cross the Evros River and begin the liberation of Eastern Thrace.
- July 25: The Greeks take Edirne during the first Greek offensive of the Greco-Turkish War (1919-1922).
- July 26: King Alexander visits newly-liberated Adrianoupolis (Edirne).
- July 30: Two former officers - Tserepis and Kyriakis - fire ten shots at Eleftherios Venizelos at the train station of Lyon, France. The Greek PM escapes death.
- July 31: Ion Dragoumis is shot dead by policemen in Athens. The nationalist politician was believed to have been involved in the Venizelos murder attempt.
- August 1: Greek forces complete the occupation of Eastern Thrace.
- August 7: The Greek Army enters Kios.
- August 10: The Treaty of Sevres is signed creating the "Greece of two continents and five seas".
- August 28: The Greek National Football Team play their first international game against Sweden and lose 9-0. EPO does not recognize this as an official game as it was not established yet; football was under the auspices of SEGAS.
- September 30: King Alexander of Greece is bitten in the left leg by a monkey in the royal gardens. The bite will prove fatal.
- November 14: Eleftherios Venizelos loses the general elections to Dimitrios Gounaris.
- November 22: Leonidas Paraskevopoulos is replaced by Anastasios Papoulas as Commander in Chief of Greek forces in Asia Minor.
- December 5: A referendum is held for the return of King Constantine I to Greece as a monarch.
- December 15: Britain and France announce that, after the return of King Constantine I, they are no longer responsible for the presence of the Greek army in Asia Minor.
- October 12: Konstantinos Giataganas, athlete (discus, shot put)
- October 18: Melina Mercouri, actress, activist and politician
- Date Unknown: Nikolaos Zorbas, military man, reformer