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 (Greek: Ἑλληνικὴ Δημοκρατία [eliniˈci ðimokraˈti.a]) or more commonly as Greece (Greek: Ἑλλάς [eˈlas], Hellas). It occupied virtually the coterminous territory of modern Greece (with the exception of the Dodecanese) 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.

The fall of the monarchy was proclaimed by the country's parliament on 25 March 1924. A relatively small country with a population of 6.2 million in 1928, it covered a total area of 130,199 km² (50,270 sq mi). Over its eleven-year history, the Second Republic saw some of the most important historical events in modern Greek history emerge; from Greece's first military dictatorship, to the short-lived democratic form of governance that followed, the normalisation of Greco-Turkish relations which lasted until the 1950s, and to the first successful efforts to significantly industrialise the nation.

The Second Hellenic Republic was abolished on 10 October 1935, with its abolition being confirmed by referendum on 3 November; this referendum was widely believed to have been mired with electoral fraud. The fall of the Republic eventually paved the way for Greece to become a totalitarian single-party state, when Ioannis Metaxas established the 4th of August Regime in 1936, lasting until the Axis occupation of Greece in 1941.

When the Republic was proclaimed on 25 March 1924, the official name adopted for the country was Hellenic State (Greek: Ἑλληνικὴ Πολιτεία). However, the name was changed to Hellenic Republic (Greek: Ἑλληνικὴ Δημοκρατία) on 24 May 1924 by vote of the Parliament. Accordingly, the title of the country's head of state was changed from Governor (Greek: Κυβερνήτης) to President of the Republic (Greek: Πρόεδρος της Δημοκρατίας). This was done to avoid any confusion as to the meaning of the terms. The word Δημοκρατία (dimokratía), used in the official name to mean Republic, translates as "democracy" as well.

In everyday speech the country was simply known as Greece. In the official variant of Greek that was the language of state, known as Katharevousa, this was Ἑλλάς (Ellás). In Demotic, or 'popular Greek', it was Ἑλλάδα (Elláda). Sometimes, the name Hellas was used in English as well.

The collapse of the Hellenic Army in Asia Minor was quickly followed by the collapse of the government. Public outrage at the Asia Minor disaster, as Greece's defeat in the war became known, was partially reflected in the military coup which followed it. The coup, orchestrated by army officers, took the name The Revolution. Although The Revolution itself did not abolish the monarchy, one of its first acts was to shut down all the royalist newspapers as well as use the Armed Forces to prosecute known royalists (including Ioannis Metaxas, who was forced to flee abroad). The decision whether or not to abolish the monarchy is one which divided Greek society, as even some Liberal Party supporters, including the Party's founder, Eleftherios Venizelos, spoke out in favour of retaining the monarchy as a safety net against instability.

After the defeat of Greece by the Turkish National Movement (the "Asia Minor Catastrophe") of 1922, the defeated army revolted against the royal government. Under Venizelist officers like Nikolaos Plastiras and Stylianos Gonatas, King Constantine I was again forced to abdicate, and died in exile in 1923. His eldest son and successor, King George II, was soon after asked by the parliament to leave Greece so the nation could decide what form of government it should adopt. In a 1924 plebiscite, Greeks voted to create a republic. These events marked the culmination of a process that had begun in 1915 between King Constantine and his political nemesis, Eleftherios Venizelos.

However, and despite the plebiscite, in the closing chapter of his History of the Greek Nation from Antiquity until 1930, Pavlos Karolidis notes that although the question of the form of government had been settled formally, it remained unresolved in the national consciousness. He goes on to add that "the regime change was carried out by men who imposed their preferred form of government posthaste as representatives of the sovereign people so as to educate them, but this is considered by many not to be a true expression of the national conscience and will".