Niall Diarmid Campbell, 10th and 3rd Duke of Argyll was a Scottish peer and historian, the 10th Duke of Argyll and 25th Chief of Clan Campbell.

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.