Sir Thomas Littleton, 3rd Baronet (3 April 1647 – 31 December 1709), often Thomas de Littleton, was an English and British statesman from the extended Littleton/Lyttelton family.
The son of Sir Thomas Littleton, 2nd Baronet (died 1681), by his wife and cousin Anne Littleton, he was related to Thomas de Littleton, a 15th-century jurist and legal theorist.
He served as Speaker of the House of Commons of England from 1698 to 1700, then as Treasurer of the Navy until his death. Macaulay thus sums up the character of Speaker Littleton and his relations with the Whigs: "He was one of their ablest, most zealous and most steadfast friends; and had been, both in the House of Commons and at the board of treasury, an invaluable second to Montague" (the Earl of Halifax).
Upon his death, without issue in 1709, the baronetcy expired, but his estate passed to his first cousin Mrs Elizabeth Meynell, the daughter of his uncle Edward Littleton.