Nectarius of Vienne was a semi-legendary bishop of Vienne who is believed to have lived during the 5th century. While some historical accounts place him in the 4th century during the reign of Constantius II, his exact biography remains uncertain. He is recognized as a pre-congregational saint within the Roman Catholic Church. His historical existence is debated by scholars, as some suggest his inclusion in early chronicles may have been intended to provide a prominent figure for the church in Vienne.