Prince Dun of the First Rank, or simply Prince Dun, was the title of a princely peerage used in China during the Manchu-led Qing dynasty (1644–1912).
As the Prince Dun peerage was not awarded "iron-cap" status, this meant that each successive bearer of the title would normally start off with a title downgraded by one rank vis-à-vis that held by his predecessor.
However, the title would generally not be downgraded to any lower than a feng'en fuguo gong except under special circumstances.
The first bearer of the title was Miankai (綿愷; 1795–1838), the Jiaqing Emperor's third son, who was made "Prince Dun of the First Rank" in 1821.
The title was passed down over four generations and held by five persons.