| Honorific-Prefix: | The Right Honourable |
| The Earl of Kinnoull | |
| Office: | Lord Lyon King of Arms |
| Term Start: | 1804 |
| Term End: | 1866 |
| Predecessor: | Robert Hay-Drummond |
| Successor: | George Burnett |
| Term Start2: | 1830 |
| Term End2: | 1866 |
| Predecessor2: | The Duke of Atholl |
| Successor2: | The Lord Kinnaird |
| Birth Date: | 5 April 1785 |
| Birth Place: | Bath, Somerset |
| Death Place: | Torquay, Devon |
| Children: | 9, including George |
Thomas Robert Hay-Drummond, 11th Earl of Kinnoull (5 April 1785 – 18 February 1866), styled Viscount Dupplin between 1787 and 1804, was a Scottish peer. His titles were Earl of Kinnoull, Viscount Dupplin and Lord Hay of Kinfauns in the Peerage of Scotland; and Baron Hay of Pedwardine in the Peerage of Great Britain.
Hay-Drummond was born in Bath, Somerset, the son of Robert Hay-Drummond, 10th Earl of Kinnoull and his second wife, Sarah Harley, daughter of Thomas Harley, Lord Mayor of London.[1] [2] Hay served as Lord Lyon King of Arms from 1804 until 1866, succeeding his father in that office.
He served as colonel of the Perthshire Militia from 1809 to 1855, and from 1830 to 1866 he was Lord Lieutenant of Perthshire.[3]
Lord Kinnoull married Louisa Burton Rowley, daughter of Sir Charles Rowley, 1st Baronet, on 17 August 1824. They had nine children:[4]
He died in Torquay, Devon, where he had lived the last six months of his life. The earldom passed to his eldest son, George.