The 4th of August Regime (Greek: Καθεστώς της 4ης Αυγούστου, romanized: Kathestós tis tetártis Avgoústou), commonly also known as the Metaxas regime (Καθεστώς Μεταξά, Kathestós Metaxá), was a dictatorial regime under the leadership of General Ioannis Metaxas that ruled the Kingdom of Greece from 1936 to 1941.
On 4 August 1936, Metaxas, with the support of King George II, suspended the Greek parliament and went on to preside over a conservative, staunchly anti-communist and ultranationalist government under the ideology of Metaxism, which has been described either as an authoritarian conservative system or as a Greek variation of Fascism; a middle position is that it was a regime with a strong Fascist component or a para-fascist regime. Metaxas himself and some contemporary historians have described the government as totalitarian. In its symbolism and rhetoric, the regime took inspiration from Fascist Italy, but it retained close links to Britain and the French Third Republic, rather than the Axis powers.