The Barony of Vaud was an appanage of the County of Savoy, corresponding roughly to the modern Canton of Vaud in Switzerland. It was created by a process of acquisition on the part of a younger brother of the reigning count beginning in 1234 and culminated in the formalisation of its relationship to the county in 1286. It was semi-independent state, capable of entering into relations with its sovereign, the Holy Roman Emperor (as in 1284), and of fighting alongside the French in the Hundred Years' War. It ceased to exist when it was bought by the count in 1359. It was then integrated into the Savoyard state, where the title Baron of Vaud (Italian barone di Vaud) remained a subsidiary title of the heads of the family at least as late as the reign of Charles Albert of Sardinia, although the territory of the barony was annexed by the Canton of Bern during the Protestant Reformation (1536).
The pays de Vaud at the time of the its purchase by the Count of Savoy in 1359 comprised fertile farmland probably yielding more revenues annually than the neighbouring County of Geneva. It lay between the lakes Geneva and Neuchâtel, and between Lausanne, which was the seat of the Bishop of Lausanne, to the west and Bern, which was a self-governing commune, to the east. It lay on important trade routes leading from the Alpine passes of the Great St Bernard and Simplon along its lakeside paths northwards into Germany and westward into France.