Sidonius was the third Bishop of Passau from about 754 to 763–764. Sidonius appears in a donation deed of the Passau domicile. He was a monk from Ireland who distinguished himself as a scientifically high-ranking theologian and probably belonged to the later Salzburg bishop Virgil of Salzburg's social circle. References Year of birth unknown 8th-century bishops in Bavaria Roman Catholic bishops of Passau