- January 24: A powerful earthquake (6.8 on the Richter scale) strikes Kefalonia and the surrounding area.
- February 8: E. Argyropoulos flies "Alcyon" - the first flight of a Greek airplane.
- March 11: The Liberal Party of Eleftherios Venizelos sweeps to victory in the Greek national elections winning 146 seats (of 181) in the Hellenic Parliament.
- March 22: Stavros Baretis assassinates Andreas Kopasis - the pro-Turkish governor of Samos.
- April 1: Kostas Tsiklitiras breaks Ray Ewry's world record in the standing broad jump with 3.47m.
- April 5: Many Asia Minor Greeks cannot vote in the Turkish elections as Young Turks vandalise many polling places, burning ballots or electoral registers.
- April 12: Italian troops start their invasion of the Dodecanese islands.
- April 26: Italian forces capture Rhodes.
- May 13: First lieutenant Dimitrios Kamberos flies the first military plane in Greek history: a Henry Farman aircraft.
- June 24: Four people die during a heatwave in Athens.
- June 25: Konstantinos Tsiklitiras wins gold, in the standing broad jump, in the 1912 Olympiad.
- August 27: Alexandros Karamanlakis becomes the first casualty of the Greek air force when his plane crashes in the Corinthian Gulf.
- September 15: Serbia and Bulgaria mobilise in preparation for the First Balkan War.
- September 18: Greece mobilises in preparation for the First Balkan War.
- September 30: Greece, Serbia and Bulgaria issue an ultimatum to the High Porte prior to the First Balkan War.
- October 3: Turkey rejects the ultimatum presented by Greece, Serbia and Bulgaria.
- October 5: The Greek Army invades Turkish Thessaly.
- October 8: Greek forces land in Lemnos.
- October 9: The Battle of Sarantaporo takes place during the First Balkan War.
- October 12: Greek forces enter Kozani and Grevena.
- October 13: The Greek Army liberates Filippiada.
- October 16: Greek forces enter Veria and Katerini.
- October 18: Greek forces land in Thasos, Imvros and Agios Efstratios.
- October 20: The Battle of Giannitsa takes place during the First Balkan War.
- October 24: During the First Balkan War, the Greek Army crosses the Axios River and advances towards Thessaloniki.
- October 24: The Battle of Pente Pigadia commences during the First Balkan War.
- October 26: The Greek army liberates Thessaloniki
- October 30: The Battle of Pente Pigadia ends in victory for the Greek Army.
- November 4: Icaria is liberated.
- November 8: Greek forces enter the city of Mytilene.
- November 11: Greek forces enter Kastoria.
- November 24: The union of Samos to Greece is declared.
- November 26: The battle of Driskos commences on the Epirus front.
- December 3: The Greek Navy led by Rear Admiral Pavlos Kountouriotis on board the flagship Averoff, forces the Ottoman navy to retreat to the Dardanelles
- December 5: Greece uses for the first time airplanes to drop bombs at Bizani
- December 16: The Greek Navy led by Rear Admiral Pavlos Kountouriotis, on board the flagship Averoff, defeats the Ottoman Navy at the Naval Battle of Elli.
- Date Unknown: Ioannis Alevras, politician
- Date Unknown: Odysseus Angelis, general, member of Junta
- Date Unknown: Argyris Argyriadis, footballer
- Date Unknown: Yiannis Chelmis, footballer
- Date Unknown: Mitsos Lygizos, actor
- Date Unknown: Spyros Sklavounos, footballer
- Date Unknown: Giorgos Vagiakakos, footballer
- Date Unknown: Kostas Yiannaros, footballer