Baptist successionism is one of several theories on the origin and continuation of Baptist churches. The theory postulates an unbroken lineage of churches which have held beliefs similar to those of current Baptists. Groups often included in this lineage include the Montanists, Paulicians, Cathari, Waldenses, Albigenses, Lollards, and Anabaptists. However most scholars agree that the Baptists originated within 17th-century puritanism, meaning it is not accepted by scholars as factual.

The Waldensians, also known as Waldenses, Vallenses, Valdesi, or Vaudois, are adherents of a church tradition that began as an ascetic movement within Western Christianity before the Reformation. Originally known as the Poor of Lyon in the late twelfth century, the movement spread to the Cottian Alps in what is today France and Italy. The founding of the Waldensians is attributed to Peter Waldo, a wealthy merchant who gave away his property around 1173, preaching apostolic poverty as the way to perfection.