Charles conferred the title on the former Earl of Wessex in celebration of Edward's 59th birthday on Friday.
Sophie, the former Countess of Wessex, is now the Duchess of Edinburgh and their 15-year-old son James, Viscount Severn is the new Earl of Wessex.
It comes after another title change this week when the Duke and Duchess of Sussex began officially using the titles Prince and Princess for their children Archie and Lilibet.
The new duke and duchess will be in Edinburgh - their first outing with their new titles in the city which inspired their name - later on Friday at a reception to mark the first year of conflict in Ukraine
Buckingham Palace said in a statement: "His Majesty The King has been pleased to confer the Dukedom of Edinburgh upon the Prince Edward, on the occasion of HRH's 59th birthday today.
"The title will be held for HRH's lifetime.
"The dukedom was last created for Prince Philip in 1947, upon his marriage to Princess Elizabeth, who held the title of Duchess of Edinburgh before acceding to the throne in 1952.
"The new Duke and Duchess of Edinburgh are proud to continue Prince Philip's legacy of promoting opportunities for young people of all backgrounds to reach their full potential."
The dukedom - which in the past has been hereditary - will not, however, pass down to the Edinburghs' son James when Edward dies.
This paves the way for one of the Prince and Princess of Wales' children to potentially be given the title in the future, with Prince Louis the most likely candidate.
James will become the Earl of Wessex and Forfar when the title of the Duke of Edinburgh reverts to the Crown, the Palace said.
Edward will also remain for his lifetime the Earl of Forfar, another of his titles, but will use the Duke of Edinburgh because it is the more senior Scottish title.
Philip had always wanted his youngest son Edward to inherit his title, but the decision ultimately was down to Charles as King.
When Prince Edward and Sophie Rhys-Jones married in 1999, they were given the titles the Earl and Countess of Wessex.
But Buckingham Palace also announced Edward would eventually one day succeed his father as the Duke of Edinburgh - but not until after the death of both Philip and the Queen.
In keeping with the Letters Patent issued when King George VI gave Philip the title in 1947, Charles inherited the Edinburgh dukedom when Philip died - but he did not use it.
On the death of the Queen six months ago, Charles acceded to the throne and the title merged with the crown and could be granted to someone else
Philip's desire for Edward to have the title was in recognition of his son's decades-long commitment to the Duke of Edinburgh's Award, the youth scheme which is one of Philip's greatest legacies.
The late monarch held the courtesy title of Duchess of Edinburgh following her marriage, as did the Queen Consort when Charles inherited the title.
The changes were swiftly updated on the royal family's website on Friday morning, minutes after the official announcement.
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