Ioannis Vlachos (Greek: Ιωάννης Βλάχος), better known as Daskalogiannis (Δασκαλογιάννης; 1722/30 – 17 June 1771), was a wealthy shipbuilder and shipowner who led a Cretan revolt against Ottoman rule in the 18th century.

Daskalogiannis agreed to fund and organize a rebellion in Sfakia against the Turkish authorities when the Russian emissaries promised to support him.

In the spring of 1770, Daskalogiannis made preparations for the revolt; he brought together men, rifles, and supplies and had defenses built at strategic locations.

The uprising began on 25 March 1770, the rebels attacked the areas of Kydonia, Apokoronas and Agios Vasilios, north east of Lefka Ori.

The rebels at first, put the Turks to flight and parts of Crete had the attributes of an independent nation, including its own coins minted in a cave near Hora Sfakion.

When the Turks attacked Daskalogiannis and his men on the Krapi plateau, the rebels suffered a crushing defeat and had to take refuge in the high mountains.

On 17 June 1771 Daskalogiannis was, in the full daylight of publicity, tortured, skinned alive and then beaten to death, an ordeal that he endured in complete silence.