Peter Waldo, Valdo, Valdes, or Waldes (c. 1140 – c. 1218), also Pierre Vaudès or de Vaux, is credited as the founder of the Waldensians, a Christian spiritual movement of the Middle Ages, descendants of which still exist in various regions of southern Europe.

Due to lack of reliable documentation there is a great degree of debate over Waldo's role in the Waldensian sect, which may have existed before his leadership.

The French historian Thuanus dated his death to the year 1179.