Cardinal Firmian

Leopold Ernst von Firmian (1708–1783) was an Austrian bishop and Cardinal.

He was Bishop of Seckau from 1739 to 1763, campaigning against Protestantism. He also acted as coadjutor bishop or administrator of the Bishopric of Trento, from 1748 to 1758. As Prince-Bishop of Passau from 1763 to 1783, he was a more tolerant reforming Catholic. He became Cardinal of S. Pietro in Montorio in 1772.

His parents were Baron Franz Alfons Georg von Firmian and Countess Barbara Elisabeth von Thun. Leopold Anton Freiherr von Firmian, archbishop of Salzburg, was his uncle. His younger brother was the Austrian plenipotentiary of Milan, Charles Joseph von Firmian.