Pierre Viret (born 1511, Orbe, Switz.—died May 4, 1571, Orthez, Fr.) was a champion of the Reformation in the Swiss canton of the Vaud and the most important native religious Reformer of French-speaking Switzerland.
In 1531 Viret came under the influence of the fugitive French religious Reformer Guillaume Farel and began preaching in the Vaud soon after. As pastor at Neuchâtel (1533), he won the favour of the Bernese, who, following their annexation of the Vaud (1536), supported his reforming efforts in the Vaudois capital of Lausanne. Viret led the disputation of Lausanne (October 1536) and subsequently organized the Reformed Church throughout the Vaud. His lengthy pastorate at Lausanne was disrupted by disagreements with the Bernese, however, and in 1559 he was forced to leave the city. Viret died in the service of Jeanne d’Albret (the mother of the future French king Henry IV) as a professor at the academy in Orthez.