Roman Catholic martyr executed during the persecution of Roman Catholics under the English queen Elizabeth I.

Mayne was raised and ordained (1561) in the Church of England. While at the University of Oxford he was befriended by Edmund Campion (Campion, Saint Edmund) (who was to become perhaps the most famous of the English Catholic martyrs) and Gregory Martin (Martin, Gregory) (later the principal translator of the Douai-Reims Bible). Under their influence, Mayne also converted to Roman Catholicism. He fled to the European continent; was ordained a Roman Catholic priest at the English College at Douai, France; and returned in 1576 as a missionary to Cornwall. He disguised himself as the steward of a local landowner but was discovered and put to death at Launceston on Nov. 30, 1577, on charges of denying the queen's spiritual supremacy, saying Mass, and possessing an Agnus Dei (a type of Roman Catholic devotional medallion). Mayne was the first of the Douai-trained priests to be martyred and, with 39 other British martyrs (the Forty Martyrs of England and Wales), was canonized by Pope Paul VI in 1970, on October 25, the day designated as their feast day.