Thomas Bruce, 2nd Earl of Ailesbury and 3rd Earl of Elgin (1656 – 16 December 1741) was the son of Robert Bruce, 2nd Earl of Elgin and Lady Diana Grey. His maternal grandparents were Henry Grey, 1st Earl of Stamford and Lady Anne Cecil, daughter of William Cecil, 2nd Earl of Exeter. His Memoirs, not published until long after his death, are a valuable source for English history in the last quarter of the seventeenth century.