Ursinus the Abbot (seventh century) was an abbot of Saint-Martin at Ligugé, and presumed biographer of Saint Leodegar. He began his career as a monk in the at Poitiers in Neustria. Ursinus later became the abbot of the monastery of Saint-Martin, where he spent the rest of his days. During his tenure he built a basilica, which became a place of honor to such a degree that in 782 it received the relics of sainted Leodegar. Ursinus also commissioned the monk Defensor to compile the florilegium Liber scintillarum from the patristic writings in the abbey's collection.