Wearing a magnificent Honiton lace gown, the third in line to the throne was baptised in a 45-minute service in the Chapel Royal of St James's Palace.
It was the first time that four generations of the royal family have been photographed together 1894 in the historic ceremony conducted by the Archbishop of Canterbury.
The chapel is significant to the couple as it is where William's mother Diana, Princess of Wales lay at rest ahead of her funeral in 1997 and Kate was confirmed there shortly before their wedding.
For the service baby George wore a Honiton lace christening gown modelled on that made for Queen Victoria's daughter in 1841. The original was replaced with one designed by the current monarch's dresser Angela Kelly after it became too fragile from generations of use.
The hymns chosen by the Duke and Duchess of Cambridge for the ceremony were Breathe On Me, Breath Of God and Be Thou My Vision.
Viscount Severn, the son of the Earl and Countess of Wessex, became the first royal baby to wear the new robe in 2008.
On Wednesday, George was photographed in it alongside the Queen, Prince Charles and his father William - making this the first time since 1894 that a monarch and three of her heirs have been captured in the same image.
The last time that happened was when Queen Victoria was photographed with her son, later Edward VII, grandson, who became George V and great-grandson, who reigned briefly as Edward VIII before abdicating.
Celebrity photographer Jason Bell, whose subjects include Nicole Kidman, David Beckham and Kate Winslet, was commissioned to take the official pictures of the occasion.
New parents William and Kate surprised many with their choice of godparents. The only member of their two families given the honour is William's cousin Zara Phillips. The seven-strong list also includes William van Cutsem, the son of Prince Charles' late friend Hugh van Cutsem.
They are joined by one of the couple's university friends Oliver Baker, Kate's childhood friend Emilia Jardine-Paterson, Earl Grosvenor, royal aide Jamie Lowther-Pinkerton and Julia Samuel, who was close to Diana, Princess of Wales.
Emilia is a friend of Kate's from Marlborough College, while Oliver Baker was at St Andrews with the royal parents. Hugh Grosvenor is the heir to the Duke of Westminster and the son of one of Diana's friends.
Michael and Julia Samuel and Earl Grosvenor
William and Kate asked the Archbishop of Canterbury Justin Welby to preside over the service.
Ahead of the special day, he told the new parents that their child is "an amazing gift", but warned of "tough times as there always are with children".
He went on: "All babies are unbelievably special, not only royal babies. As a nation we are celebrating the birth of someone who will in due course be the head of State. That's extraordinary."