Ignaz Heinrich von Wessenberg (4 November 1774 – 9 August 1860) was a German writer and scholar, and liberal Catholic churchman as well as Vicar general and administrator of the Diocese of Constance. Imbued from his early youth with Josephinistic and Febronian principles, he advocated a German National Church, somewhat loosely connected with Rome, supported by the State and protected by it against papal interference.
Ignaz Heinrich was born at Dresden, where his father worked as a tutor of the princes of the electoral House of Wettin. In 1776 his family returned to Freiburg in Further Austria. His elder brother Johann von Wessenberg later entered the diplomatic service of the Habsburg Monarchy.
Ignaz von Wessenberg studied theology at the Jesuit school of Augsburg and the universities of Dillingen, Würzburg and Vienna. At the age of eighteen he was already canon at Constance, Augsburg and Basel, and in 1802, when still a subdeacon, he was appointed Vicar general for the Diocese of Constance by Prince-Bishop Karl Theodor von Dalberg. It was only in 1812 that he was ordained a priest at age 38.