Ian Campbell, 12th and 5th Duke of Argyll,, styled Marquess of Lorne between 1949 and 1973, was a Scottish peer and Chief of Clan Campbell. He was the 12th Duke of Argyll in the Peerage of Scotland, 5th Duke of Argyll in the Peerage of the United Kingdom and Lord Lieutenant of Argyll and Bute.

Duke of Argyll is a title created in the peerage of Scotland in 1701 and in the peerage of the United Kingdom in 1892. The earls, marquesses, and dukes of Argyll were for several centuries among the most powerful noble families in Scotland. As such, they played a major role in Scottish history throughout the 16th, 17th, and 18th centuries. The Duke of Argyll also holds the hereditary titles of chief of Clan Campbell and Master of the Household of Scotland.