Thomas Fiennes, 9th Baron Dacre (c. 1516 – 1541) was an English nobleman notable for his conviction and execution for murder.

[1] He was born in or before 1516, the son and heir of Sir Thomas Fiennes and Jane (d. 1539), daughter of Edward Sutton, 2nd Baron Dudley.

[1] In 1536 he married Mary, daughter of George Neville, 5th Baron Bergavenny and his third wife, Mary, daughter of Edward Stafford, 3rd Duke of Buckingham, by whom he had three children: He was a member of the jury at the trial of Anne Boleyn in 1536, and of Thomas, Lord Darcy, and John, Lord Hussey in May 1537 (for their part in the Pilgrimage of Grace), and of Baron Montagu and the Marquess of Exeter in 1538 for the Exeter Conspiracy.

[1] In October 1537, he attended the baptism of Prince Edward and bore the canopy at Queen Jane's funeral the following month.

[3] An account of the execution in Hall's Chronicle says: His only sister Anne's husband, John Mantell, was hanged along with his brother-in-law.