John George I (1585-1656) was Elector of Saxony from 1611 to 1656.
He was the son of the Elector Christian I of Saxony and Sophie of Brandenburg.
His personal allegiance to Lutheranism was sound. He liked neither the growing strength of Brandenburg nor the increasing prestige of the Palatinate.
In May 1635 John George I concluded the Treaty of Prague with the Holy Emperor Ferdinand II. Saxony received Lusatia and certain other additions of territory.
Holy Roman Emperor Ferdinand II secured the help of John George I for the impending campaign in Bohemia by promising that he should be undisturbed in his possession of certain ecclesiastical lands.