John Hay, 1st Lord Hay of Yester (c. 1450 – after October 1508) is the ancestor of the Marquesses of Tweeddale. He was created a Lord of Parliament on 29 January 1488 by James III of Scotland.
He was born in Peebleshire, the son of Sir David Hay of Locherworth, Peebleshire, and later Yester in East Lothian (d. c. 1478) by his wife Elizabeth (b. c. 1400), daughter of George Douglas, 1st Earl of Angus (1370–1402) by Princess Mary (d. before 1458), daughter of Robert III, King of Scots.
John Hay married (1) Mary (d. c. 1467), daughter of John Lindsay, 1st Lord Lindsay of the Byres, and (2) by contract before 17 December 1468, Elizabeth (d. 1529), daughter of George Cunningham of Belton. There were children by both marriages: