Lady Mary FitzAlan, Duchess of Norfolk (1540 – 23/25 August 1557) was the youngest daughter and child of Henry FitzAlan, 19th Earl of Arundel and his first wife Lady Catherine Grey. Because her only brother had predeceased her, she and her elder sister, Jane FitzAlan were co-heiresses to the earldom of her father. Mary and Jane both received an excellent education.