Peregrine Bertie, 2nd Duke of Ancaster and Kesteven PC (29 April 1686 – 1 January 1742), styled The Honourable Peregrine Bertie between 1686 and 1704, Lord Willoughby de Eresby between 1704 and 1715 and Marquess of Lindsey between 1715 and 1723, was a British politician who sat in the House of Commons from 1708 until 1715 when he was called to the House of Lords.