1544-1577. English Roman Catholic martyr. Born in Devon, he was educated at Oxford, and after Anglican ordination was appointed chaplain of St. John's College there, where was a colleague. Under the latter's influence Mayne was converted to , and in 1573 went to the newly founded English seminary at Douai. Ordained priest in 1575, he returned to England in the following year and settled, ostensibly as steward, at Francis Tregian's estate in Cornwall. He secretly carried out his priestly functions until his arrest in 1577. Despite some disagreement among judges, he was condemned for refusing to take the oath of royal supremacy and for celebrating Mass, and was executed at Launceston. He was beatified in 1888.