Peregrine Bertie, 2nd Duke of Ancaster and Kesteven (29 April 1686 - 1 January 1742), also known as Peregrine Bertie (1686-1701), Lord Willoughby de Eresby (1701-1715) and Marquess of Lindsey (1715-1723), was a British nobleman and statesman.

Bertie, who matriculated at Oxford in the late 17th century, graduated from that university in 1702 and was appointed Vice Chamberlain to Queen Anne. In 1708, he entered Parliament as MP for Lincolnshire, and was invested a Privy Counsellor that same year. He would serve in the House of Commons until he was summoned to the House of Lords by Writ in Acceleration in his father's Barony of Willoughby de Eresby in 1715. While serving as a Gentleman of the Bedchamber, Lord Willougby de Eresby inherited the rest of his father's titles on his death in 1723; he also inherited the hereditary Great Office of Lord Great Chamberlain and was made Lord-Lieutenant of Lincolnshire in his late father's place. He served in these capacities, and also in the House of Lords, gaining the additional position of Lord Warden and Justice in Eyre until his death in 1742.