The Duke of Hue is the premier Duke in the peerage of Vietnam. The Duke of Hue is, by custom, the Governor-General of Vietnam. The seat of the Duke of Hue is the Purple Forbidden City (Tử Cấm Thành) in the Capital of Hue. The current duke is HRH Bao Long, 2nd Duke of Hue. The inaugural holder was HRH Bao Dai, 1st Duke of Hue.
The Duchy of Hue was created by letter patents of King George VI for Bao Dai, former Emperor of Vietnam after British rule was installed in Vietnam in 1945. Bao Dai was the nominal head of Viet Nam, although without any actual powers, during French colonial rule. The Duke of Hue is the only entity outside the British Royal Family to be granted the style of His Royal Highness.