Gautbert was a ninth-century Catholic bishop who served as the fourth Bishop of Osnabrück from 845 until his death in 860. A relative of Ebo, the Archbishop of Reims, he was consecrated as a missionary bishop with the name Simon to continue the work of Ansgar in southern Sweden. Although he established a presence in Birka and built a church there, a violent uprising in 845 forced him to leave the region, after which he focused his ministry on his role in Osnabrück.