Adso of Montier-en-Der was a tenth-century monk and later abbot of the Vosges monastery of Montier-en-Der, ending his career as abbot of Saint-Bénigne in Dijon. He wrote lives of Saints Frodobert, Bercharius and Mansuetus, but is remembered above all for his Libellus de Antichristo, a tract on the career of Antichrist addressed to Queen Gerberga, which shaped medieval expectations of the last days.