Ternan was a fifth or sixth-century bishop of the Picts who played a significant role in early Scottish Christianity. Although historical details regarding his life are sparse, he is recognized as a monastic figure who likely studied at Whithorn. Serving as a bishop, he resided at Abernethy and worked alongside his assistant, Irchard, to spread the gospel. He is remembered for establishing a monastery near the River Dee, where he and his followers taught local communities various skills, including farming and crafts.