Avitus was the son of Bishop Hesychius of Vienne, whom he succeeded around 490 — the senatorial Gallo-Roman family of Sidonius Apollinaris formed his cousins. He governed the see of Vienne for over thirty years, during which he was the principal Latin theologian and diplomatic figure of the Burgundian kingdom.
His correspondence with King Sigismund of Burgundy — whom he converted from Arianism to Catholicism around 506 — and his theological treatises against the Arians make him the central figure of the Burgundian Catholic restoration. He presided at the Council of Epaone (517) that reorganized Burgundian Church life.
His Latin verse — particularly the De Spiritualis Historiae Gestis ('On the Deeds of Spiritual History') in five books on Genesis and Exodus, often called simply the Carmina — is among the most accomplished Latin Christian poetry of late antiquity, foundational for later medieval reception of the Old Testament. The Carmina influenced Milton's Paradise Lost through Renaissance scholarly editions.
He died at Vienne in 525 and is venerated as a saint in both Latin and Eastern calendars.