Duke of Gloucester and Edinburgh (/ˈɡlɒstər/ GLOST-ər) was a British title (after Gloucester and Edinburgh) in the Peerage of Great Britain; the sole creation carried with it the subsidiary title of Earl of Connaught.

It existed for the brother of King George III, Prince William Henry; there had been Dukedoms of Gloucester and of Edinburgh but their extinction gave the opportunity for combination.

The dukedom of Gloucester and Edinburgh was a royal dukedom when the duke was entitled to the style "His Royal Highness", as Prince William Henry was, but Prince William Frederick was only granted this style on his marriage in 1816.^[1]

After the Union of Great Britain, the Hanoverian kings liked to grant double titles (one from one constituent country, one from another) to emphasise unity.

Duke	Portrait	Birth	Marriage(s)	Death
Prince William Henry House of Hanover 1764–1805 also: Earl of Connaught		25 November 1743 Leicester House son of Frederick, Prince of Wales and Princess Augusta of Saxe-Gotha	Maria Walpole 1766 3 children	25 August 1805 Gloucester House aged 61
Prince William Frederick House of Hanover 1805–1834 also: Earl of Connaught		15 January 1776 Teodoli Palace son of Prince William Henry and Maria Walpole	Princess Mary of the United Kingdom (his first cousin) 1816 no children	30 November 1834 Bagshot Park aged 58
William Frederick had no children and all his titles became extinct on his death.

• Duke of Gloucester
• Duke of Edinburgh
• List of dukedoms by reign
• Earl of Gloucester