Ioannis Diakos (Greek: Ιωάννης Διάκος, c. 1805-1887) was a Greek revolutionary leader during the Greek War of Independence.

He was a chief of Pyrgos and battled during the Greek War of Independence and at the time, he was a general of Pyrgos.

Petros Mitzos killed his father in 1823 in which that in the political battlefield he also killed Stamatis Krestenitis.