John George I of Anhalt-Dessau was a German prince of the House of Ascania. From 1586 to 1603 he ruled the unified principality of Anhalt jointly with his brothers. After the partition of the principality in 1603, he ruled the principality of Anhalt-Dessau from 1603 to 1618.
John George was much appreciated by his subjects and considered learned abroad, particularly in the subjects of astrology and alchemy. He possessed a remarkable library with over 3000 volumes.