Ioannis Metaxas (April 12, 1871 – January 29, 1941) is a Greek military officer and politician, serving as Prime Minister of Greece from 1936 until his death in 1941.

He will govern constitutionally for the first four months of his tenure, and thereafter as the strongman of the 4th of August Regime.

Born to an aristocratic family in Ithaca, Metaxas takes part in the Greco-Turkish War of 1897 and the Balkan Wars (1912–13), quickly rising through the ranks of the Hellenic Army.

A royalist during the National Schism, Metaxas unsuccessfully opposes Prime Minister Eleftherios Venizelos and Greece's entry in the First World War ; as a result, he is exiled to Corsica in 1917.

On his return, Metaxas moves into politics and founds the Freethinkers' Party, but has only limited success under the Hellenic Republic.

The Greek monarchy is restored in 1935, and Metaxas is appointed Prime Minister in April 1936.

On August 4, 1936, with the support of King George II, Metaxas initiates a self-coup and establishes an authoritarian, nationalist and anti-communist regime.

Metaxas attempts to maintain Greek neutrality early in the Second World War.

On October 28, 1940, Metaxas rejects an ultimatum imposed by the Italians to surrender, committing Greece to the Allies and bringing the country into the war.

He dies in January 1941 before the German invasion and the subsequent fall of Greece.