William Egon of Fürstenberg, Catholic cardinal (d. 1704)
Wilhelm Egon von Fürstenberg-Heiligenberg (2 December 1629 – 10 April 1704) was a German count and later prince of Fürstenberg-Heiligenberg in the Holy Roman Empire. He was a clergyman who became bishop of Strasbourg, and was heavily involved in European politics after the Thirty Years' War. He worked for the Archbishop-Elector of Cologne and Louis XIV of France at the same time, and was arrested and tried for treason for convincing the Elector to fight on the opposite side of a war from the Empire.