| Mary of Lancaster | |
|---|---|
| Baroness Percy | |
| Born | c. 1320–21 Tutbury Castle, Staffordshire, England |
| Died | 1 September 1362 (aged 40–42) Alnwick, Northumberland, England |
| Spouse | Henry Percy |
| Issue | Henry Percy, 1st Earl of Northumberland Thomas Percy, 1st Earl of Worcester |
| House | Lancaster |
| Father | Henry, 3rd Earl of Lancaster |
| Mother | Maud Chaworth |
| English Royalty |
| First House of Lancaster |
|---|
 |
| Henry, 3rd Earl |
Mary of Lancaster, Baroness Percy (c. 1320–1321 – 1 September 1362), was the youngest surviving child of Henry, 3rd Earl of Lancaster by his wife Maud Chaworth. Through her father, she was a great-granddaughter of Henry III of England.