Heliodorus of Altino was a 4th-century bishop who served as the first leader of the see of Altinum. Born in Dalmatia, he was a student of Valerianus, the bishop of Aquileia, and traveled to the Holy Land alongside Jerome. After his mother passed away, he moved to Italy to take up his episcopal duties. During his tenure, he worked to oppose Arianism and participated in the Council of Aquileia in 381.