Gilbert Hay, or Sir Gilbert the Haye (b. c.1403; last mentioned in 1456) was a Scottish poet and translator and, perhaps, a kinsman of the house of Errol.
If he is the student named in the registers of the University of St Andrews in 1418-1419, his birth may be fixed about 1403. He was in France in 1432, perhaps some years earlier, for a "Gilbert de la Haye" is mentioned as present at Reims, in July 1430, at the coronation of Charles VII. He has left it on record, in the Prologue to his Buke of the Law of Armys, that he was "chaumerlayn umquhyle to the maist worthy King Charles of France." In 1456 he was back in Scotland, in the service of the chancellor, William, Earl of Orkney and Caithness, "in his castell of Rosselyn," south of Edinburgh. The date of his death is unknown.
Hay is named by Dunbar in his Lament for the Makaris, and by Sir David Lyndsay in his Testament and Complaynt of the Papyngo. His only poetic work is The Buik of King Alexander the Conquerour, of which a portion, in copy, formerly at Taymouth Castle, now lies in the National Records of Scotland.
He has left three translations, extant in one volume (in old binding) in the collection of Abbotsford: The Buke of the Law of Armysor The Buke of Bataillis, a translation of Honoré Bonet's Arbre des batailles; The Buke of the Order of Knichthood from the Livre de l'ordre de chevalerie (Llibre qui es de l'ordre de cavalleria) of Ramon Llull; and The Buke of the Governaunce of Princes, from a French version of the pseudo-Aristotelian Secreta secretorum. The second of these precedes Caxton's independent translation by at least ten years.