The royalist Leonardopoulos–Gargalidis coup d'état attempt fails in Greece, discrediting the monarchy and paving the way for the establishment of the Second Hellenic Republic.

The Leonardopoulos–Gargalidis coup attempt was a failed military coup launched on 22 October 1923 in the Kingdom of Greece by pro-royalist military officers under the Lieutenant Generals Georgios Leonardopoulos and Panagiotis Gargalidis, and the Colonel Georgios Ziras. Its failure discredited the monarchy and contributed decisively to the establishment of the Second Hellenic Republic in March 1924.

The Second Hellenic Republic is a modern historiographical term used to refer to the Greek state during a period of republican governance between 1924 and 1935. To its contemporaries it was known officially as the Hellenic Republic or more commonly as Greece. It occupied virtually the coterminous territory of modern Greece and bordered Albania, Yugoslavia, Bulgaria, Turkey and the Italian Aegean Islands. The term Second Republic is used to differentiate it from the First and Third republics.

October 22 is the 295th day of the year in the Gregorian calendar; 70 days remain until the end of the year.