Lady Jane was the great-granddaughter of Henry VII through her mother, Lady Frances Brandon, whose own mother was Mary, the younger of King Henry VIII's two sisters. Provided with excellent tutors, she spoke and wrote Greek and Latin at an early age; she was also proficient in French, Hebrew, and Italian. When Lady Jane was barely nine years old she went to live in the household of Queen Catherine Parr, and on the latter's death in September 1548 she was made a ward of Catherine's fourth husband, Thomas Seymour, Lord Seymour of Sudeley (Seymour, Thomas Seymour, Baron), who planned her marriage to his nephew and her cousin, the young king Edward VI. But Seymour was beheaded for treason in 1549, and Jane returned to her studies at Bradgate.

After Lady Jane's father, hitherto Marquess of Dorset, was created Duke of Suffolk (Suffolk, Henry Grey, duke of, 3rd marquess of Dorset, Lord Ferrers of Groby, Lord Harington, Lord Bonville) in October 1551, she was constantly at the royal court. On May 21, 1553, John Dudley, Duke of Northumberland (Northumberland, John Dudley, duke of, earl of Warwick, Viscount Lisle, Baron Lisle), who exercised considerable power at that point in the minority of King Edward VI, joined with Suffolk in marrying her to his son, Lord Guildford Dudley. Her Protestantism, which was extreme, made her the natural candidate for the throne of those who supported the Reformation, such as Northumberland. With the support of Northumberland, who had persuaded the dying Edward to set aside his half-sisters Mary and Elizabeth in favour of any male heirs who might be born to the Duchess of Suffolk and, failing them, to Lady Jane, she and her male heirs were designated successors to the throne.

Edward died on July 6, 1553; on July 10, Lady Jane—who fainted when the idea was first broached to her—was proclaimed queen. However, Edward's sister Mary Tudor, the heir according to an act of Parliament (1544) and Henry VIII's will (1547), had the support of the populace, and on July 19 even Suffolk, who by now despaired of success in the plans for his daughter, attempted to retrieve his position by proclaiming Mary queen. Northumberland's supporters melted away, and the Duke of Suffolk easily persuaded his daughter to relinquish the unwanted crown. At the beginning of Mary I's reign, Lady Jane and her father were committed to the Tower of London, but he was soon pardoned. Lady Jane and her husband, however, were arraigned for high treason on Nov. 14, 1553. She pleaded guilty and was sentenced to death. The execution of the sentence was suspended, but the participation of her father, in early February 1554, in Sir Thomas Wyat's rebellion sealed her fate. She and her husband were beheaded on Feb. 12, 1554; her father was executed 11 days later.