Duke of Cambridge is a hereditary title of nobility in the British royal family, one of several royal dukedoms in the United Kingdom. The title is named after the city^[3] of Cambridge in England. It is heritable by male descendants by primogeniture, and has been conferred upon various members of the British royal family several times throughout history.

The title of Duke of Cambridge, first created in 1660, superseded an earlier title of Earl of Cambridge. The title became extinct several times before being revived in 2011, when Queen Elizabeth II bestowed it on her grandson Prince William on 29 April 2011 upon his marriage to Catherine Middleton. Catherine became known as the Duchess of Cambridge.

The title was first granted in 1660 by Charles II of England (immediately following the Restoration of the monarchy) to his infant eldest nephew Charles Stuart (1660–1661), the first son of the Duke of York (later King James II), though he was never formally created Duke of Cambridge as he died at the age of six months. The first officially recognised creation of the dukedom was in the Peerage of England in 1664, when King Charles II granted the title to his next eldest surviving nephew James Stuart, the infant second son of the Duke of York, who died early in 1667 at the age of three, when the title again became extinct. The title was then granted later that year by King Charles II to his next eldest surviving nephew Edgar Stuart, the third son of the Duke of York, who also died in infancy, in 1671 at the age of three, when the title became extinct the third time. The Duke of York's fourth son Charles (his eldest son by his second wife) was also styled Duke of Cambridge in 1677, but died when about a month old, not having lived long enough to be formally created duke.

The title was recreated by Queen Anne in 1706 who granted it to George Augustus (later King George II), son of the Elector of Hanover (later King George I), her distant cousin (both being descended from King James I). When the title was created George Augustus was third in line to the throne, after his grandmother Sophia and his father. When he ascended to the throne as King George II in 1727, the dukedom merged with the Crown.^[1]

The title was again recreated in the peerage of the United Kingdom and was granted in 1801 by King George III to his seventh son Prince Adolphus (1774–1850), then aged 27.^[4] Following his death in 1850 the title was inherited by his only son Prince George, 2nd Duke of Cambridge, whose three sons were barred from inheriting the title as his marriage had been in violation of the Royal Marriages Act 1772. Thus on the death of the 2nd Duke in 1904 the title again became extinct.^[5]

During the period leading up to the 1999 wedding of Prince Edward, the youngest son of Queen Elizabeth II, some people speculated that the Dukedom of Cambridge or Sussex were the most likely to be granted to him, and The Sunday Telegraph later reported that Prince Edward was at one point set to be titled Duke of Cambridge.^[6] Instead, Prince Edward was created Earl of Wessex, and it was announced that he would eventually be created the next Duke of Edinburgh after his father.^[7]

On 29 April 2011, the day of his wedding, it was announced that Queen Elizabeth II had created her grandson Prince William Duke of Cambridge, Earl of Strathearn and Baron Carrickfergus,^[1] titles relating respectively to places in England, Scotland and Northern Ireland, three of the constituent countries of the United Kingdom. The letters patent granting these titles received the great seal on 26 May 2011.^[2]

If William becomes king, his titles, including the dukedom, will merge with the crown. However, if he dies before becoming king, then his sons are eligible to inherit the dukedom:

• Duke of Cambridge's Personal Canadian Flag
• Marquess of Cambridge
• Earl of Cambridge