Thomas Herbert, 8th Earl of Pembroke

Thomas Herbert, 8th Earl of Pembroke and 5th Earl of Montgomery, KG, PC, FRS (c. 1656; † January 22, 1733 ) was a British politician in the reign of William III. and Anne.

He was the son of Philip Herbert, 5th Earl of Pembroke, and his wife Catharine Villiers. In 1684 he married Margaret, only daughter of Sir Robert Sawyer of Highclere. They had three children together. In the year before the marriage he had inherited both his father's earldom after his two older brothers had died without male descendants. After the death of his first wife, he married two more times, from his second marriage comes another daughter.

His political career had already begun when he was elected in 1679 in the House of Commons Herbert. In 1690 he became First Lord of the Admiralty, Lord Privy Seal in 1692. He was twice Lord High Admiral, also in 1699 Lord President of the Council and Lord Lieutenant of Ireland and one of the Lords Justices. 1689/90 he was president of the Royal Society.

His second son, Robert Sawyer Herbert, inherited Highclere Castle. John Locke dedicated his major work: An Essay Concerning Human Understanding.