Lord John Hay may refer to:
- John Hay, 1st Lord Hay of Yester (1450–1508), Scottish nobleman
- Lord John Hay (Scottish Army officer) (c. 1668–1706), Scottish general
- Lord John Hay (politician) (1788–1851), British Royal Navy officer and Whig politician
- Lord John Hay (Royal Navy officer, born 1827) (1827–1916), British Royal Navy officer and Liberal politician, nephew of the above