| Honorific-Prefix: | The Right Honourable |
| The Earl of Erroll | |
| Birth Date: | 1423 |
| Birth Place: | Errol, Perthshire, Scotland |
| Death Date: | October 1462 (age 38 or 39) |
| Office: | 5th Lord High Constable of Scotland |
| Predecessor: | William de la Haye |
| Successor: | Nicholas Hay |
| Term Start: | 1437 |
| Term End: | 1462 |
| Children: | 7, including Nicholas and William |
William Hay, 1st Earl of Erroll (1423 – October 1462) was a Scottish peer. He was the first Earl of Erroll and the second Lord Hay of Erroll.
William Hay was born in Erroll (now spelled Errol) in Perthshire, the son of Gilbert Hay and Alicia Hay, daughter of William Hay of Yester.
His paternal grandmother, Princess Elizabeth Stewart, was the youngest child of Robert II of Scotland and his first wife, Elizabeth Mure.[1]
His paternal grandfather Thomas de la Hay was the third Lord High Constable of Scotland. William Hay inherited the title in 1437 after the death of his father Sir William.[2]
In 1454, he purchased lands in Angus from Alexander Ogilvie of Auchterhouse.
On 17 March 1452, King James II of Scotland made him the first Earl of Erroll. Some historians list his death as August 1460, but Sir James Balfour Paul notes in The Scots Peerage that Kinnoull was alive in the Slains land inventory of November 1461. Balfour writes that the earl likely died in October 1462,[3] and was interred in the Abbey Church of Cupar.[2]
He married Beatrix, a daughter of James Douglas, 7th Earl of Douglas, and had three sons and four daughters:[3]
Volume 3
. 1906. D. Douglas. 564–565. Balfour Paul.