John George I of Saxony (German: Johann Georg I) (5 March 1585 – 8 October 1656) was Elector of Saxony from 1611 to 1656. His reign coincided with much of the Thirty Years' War, during which the Protestant John George often aligned with whichever side could guarantee that he would retain his lands. He was aligned for a time with Gustavus Adolphus of Sweden, but switched sides a few years later after Gustavus died.