Robert Bertie, 1st Duke of Ancaster and Kesteven, English politician, Chancellor of the Duchy of Lancaster (d. 1723)

Robert Bertie, 1st Duke of Ancaster and Kesteven PC (20 October 1660 – 26 July 1723), styled 17th Baron Willoughby de Eresby between 1666 and 1701, and known as 4th Earl of Lindsey between 1701 and 1706, and as 1st Marquess of Lindsey between 1706 and 1715, was a British statesman and nobleman.