Lady Mary Grey
| Lady Mary Keyes | |
|---|---|
| Born | 20 April 1545 | 
| Died | 20 April 1578 (aged 33) | 
| Spouse | Thomas Keyes | 
| Father | Henry Grey, 1st Duke of Suffolk | 
| Mother | Lady Frances Brandon | 
Lady Mary Keyes (née Grey; 20 April 1545 – 20 April 1578) was the youngest daughter of Henry Grey, 1st Duke of Suffolk, and Frances Brandon, and through her mother had a claim on the crown of England.