Gebhard Truchsess von Waldburg (10 November 1547 – 21 May 1601) was Archbishop-Elector of Cologne. After pursuing an ecclesiastical career, he won a close election in the Cathedral chapter of Cologne over Ernst of Bavaria. After his election, he fell in love with and later married Agnes von Mansfeld-Eisleben, a Protestant Canoness at the Abbey of Gerresheim. His conversion to Calvinism and announcement of religious parity in the Electorate triggered a war.