Aristagoras of Miletus, d. 497/496 BC, was the tyrant of the Ionian city of Miletus in the late 6th century BC and early 5th century BC. He acted as one of the instigators of the Ionian Revolt against the Persian Achaemenid Empire. He was the son-in-law of Histiaeus and was granted the tyranny of Miletus from him.