Vivianus (also Bibianus; died c. 490) was an early saint of the French (Francian) church and the first known bishop of Saintes.
A brief Life of his dated to the mid-6th century was edited by Krush in 1896. He is also mentioned by Gregory of Tours later in the 6th century, who refers to the earlier text, saying "a book that has already been written about his life narrates the bulk of his miracles".
Vivianus was born in Saintes, a city in southwestern Gaul, in the 5th Century. His father, whose name remains unrecorded, adhered to pagan beliefs throughout his lifetime, while his mother, Maurella, was a devoted Christian who played a pivotal role in his early spiritual development. Maurella instilled in Vivianus a strong foundation of Christian faith from childhood, guiding his religious background at a time of religious transition. Her influence played a critical role in nurturing his commitment to Christianity, which later propelled him toward a clerical career under Bishop Ambrosius of Saintes.
At age 16, Vivianus devoted himself to Bishop Ambrosius, the prelate of the diocese at the time. Ambrosius viewed Vivianus as his own, personally overseeing his immersion in sacred scriptures, which formed the cornerstone of his religious formation. Under Ambrosius's guidance, Vivianus underwent a comprehensive moral and intellectual development, emphasizing virtues such as humility and piety that defined his character. As his first step into clerical service, he was enrolled in the minor order of Reader, a role involving the public proclamation of scriptural lessons during liturgy, marking his entry into the church hierarchy.