He's less than three months old, but royal fans have already decided who the newest member of the Cambridge family takes after.
A photograph of Prince Louis on his christening day was posted to the Kensington Palace Instagram account on Monday, and followers were quick to point out how much Louis is starting to resemble his big brother, Prince George.
'Prince Louis looks so much like Prince George at the same age,' said one fan beneath the post, while another chimed in with 'he looks so much like George'.
'Awww so gorgeous. Louis looks like mini George,' another admirer said of the 'joyful' family photograph.
Prince Louis can be seen laughing delightedly in the arms of his proud mother Kate in an adorable candid photograph taken on his christening day in the garden at Clarence House - where his parents hosted a private tea for their nearest and dearest following his baptism at St James's Palace on 9th July.
Family resemblance: The Duke and Duchess of Cambridge shared an extra photograph from Prince Louis' christening day on Monday, which shows the newborn laughing with glee in the arms of his proud mother, Kate
The snap was posted on the Kensington Palace Instagram account, where delighted fans were quick to point out baby Louis' resemblance to his big brother, Prince George
Thousands of people have liked the photograph on Instagram, with many sharing their thoughts on who the newest member of the Cambridge family takes after
The royals' Instagram followers said Louis is a 'mini version' of his older brother, George, seen on his own christening day at St James's Palace in 2013
A message shared on the Kensington Palace Instagram account said: 'The Duke and Duchess hope that everyone enjoys this lovely photograph of Prince Louis as much as they do.'
The sweet snap reveals Prince Louis' big brown eyes, gummy smile and tufts of brown hair.
Although his big brother Prince George, now four, is now fair, as a baby he had similar brown hair to his baby brother.
None of this was lost on the Cambridge family's enormous Instagram following, one of whom wrote beneath the image: 'Wow he looks just like George!!!'
Another declared: 'A mini Prince George right there.'
While most people appeared convinced little Louis is taking after his brother, some did insist he looks just like his mother.
'He is Kate's twin,' one royal-watcher said of baby Louis.
Prince George is seen wearing the traditional Honiton replica robe - worn by every royal baby at their christening since Lady Louise Windsor. Prince Louis was also dressed in the robe for his baptism last week
Family of five: William and Kate pose proudly with their three children; Prince George, Princess Charlotte, and Prince Louis, in a formal photograph taken to mark Louis' christening
The informal snap, taken by photographer Matt Porteous, was released on Monday morning, the day after formal family portraits taken to mark Prince Louis' christening by Matt Holyoak were unveiled to the public.
The new family of five posed with the Prince of Wales and the Duchess of Cornwall, the Duke and Duchess of Sussex, and the Middleton family at Clarence House, where they enjoyed tea after the Archbishop of Canterbury baptised Louis at the Chapel Royal in St James's Palace.
The Queen and Prince Philip did not attend as they were in Norfolk when the christening was held ahead of a busy week for the Queen.
The Duke of Edinburgh has scaled back his public appearances since retiring from royal duties last year.
The formal family portraits were taken by Matt Holyoak at Clarence House, where Kate and William hosted a private tea for their nearest and dearest
WHO ARE PRINCE LOUIS' GODPARENTS?
THE LADY LAURA MEADE
Lady Laura Meade is the wife of James Meade, another Old Etonian and fast friend of Wills', who was asked to make a speech at the royal wedding and is godfather to Louis' big sister, Princess Charlotte.
William was again asked to be an usher when Laura and James tied the knot in 2013, and Kate, Prince Harry and Kate's younger sister Pippa were all among the congregation.
Laura, from Norfolk, is the daughter of the Earl and Countess of Romney, and she and her siblings are close to the Middletons as well as the Prince.
Before they married and settled down, Kate and William and Laura and James were regulars at the Cuckoo Club in Piccadilly.
Prince Louis’ godfather Harry Aubrey-Fletcher is one of William's oldest friends, having attended both Ludgrove prep school and Eton with the Prince.
Kate joined William at Harry's wedding to Louise Stourton in January 2011, just four months before the Duke and Duchess of Cambridge’s own nuptials.
Prince William was an usher at the ceremony, held at Aldborough Parish Church in Boroughbridge, West Yorkshire.
Harry is the youngest son of Sir Henry Aubrey-Fletcher, 8th Baronet and Lord Lieutenant of Buckinghamshire. His similarly blue-blooded wife, who will also attend Prince Louis' christening, is the eldest daughter of Edward Stourton, the 24th Baron Stourton, 28th Baron Segrave, 27th Baron Mowbray.
NICHOLAS VAN CUTSEM
Major Nicholas van Cutsem has been firm friends of the Prince of Wales and his sons for years.
His daughter, Grace, stole the show at the 2011 Royal wedding when she covered her ears on the balcony of Buckingham Palace.
Nicholas serves with the Household Cavalry and led the escort accompanying the Prince’s Royal Wedding carriage.
He is married to Alice van Cutsem, with the pair wedded in 2009.
Mr Pelly has been in part of Harry and William's inner circle since their teenage years.
He is known for running celebrity nightclub, Tonteria, in Chelsea, South-West London, a favourite old haunt of Harry during his partying years.
The entrepreneur has also been involved with Mahiki, Whisky Mist and Public over the years.
He welcomed his first child, a little girl Willow Elizabeth, with his Holiday Inn heiress wife Lizzy Wilson last summer.
Bristol graduate Lucy, 32, is the Duchess of Cambridge's cousin and works as a solicitor in London specialising in media litigation for Atkins Thomson.
She is said to be close to the Duchess, and the pair spent their gap year together in Florence.
Lucy was studying Italian and Catherine to join her.
HANNAH CARTER (MRS ROBERT CARTER)
Hannah and Kate attended Marlborough College together, where they played on several of the same sports teams.
Kate's sister Pippa was a couple of years below Kate at the same school and also played sports.