Earl Cawdor, of Castlemartin in the County of Pembroke, is a title in the Peerage of the United Kingdom. It was created in 1827 for John Campbell, 2nd Baron Cawdor. This branch of Clan Campbell descends from Sir John Campbell (died 1546), third son of Archibald Campbell, 2nd Earl of Argyll (whose eldest son Colin was the ancestor of the Dukes of Argyll; see the latter title for earlier history of the family). His descendant Pryse Campbell (d. 1768) represented Nairnshire in the House of Commons. His son John Campbell was Member of Parliament for Nairnshire and Cardigan. In 1796 he was raised to the Peerage of Great Britain as Baron Cawdor, of Castlemartin in the County of Pembroke.