Peter Thumb (1681–1767) was an Austrian architect whose family came from the Vorarlberg, the westernmost part of Austria. He is best known for his Rococo architecture, mainly in Southern Germany. Outstanding examples of his work include the pilgrimage church at Birnau on Lake Constance and the monastery library at the Abbey of Saint Gall, Saint Gallen, Switzerland.
His works include:
- St. Trudpert's Abbey: the nave of the abbey church, circa 1715-22, and the conventual buildings, 1738–39
- Königsbrück Abbey: the abbey church, 1721 (no longer extant)
- Ebersmunster Abbey: the abbey church, 1727
- St. Peter's Abbey in the Black Forest: the abbey church, 1724–1727, and the library, 1737–39
- Pilgrimage Church at Birnau, 1746–50
- Abbey of Saint Gall: library, 1757-67