"We are not giving details of the guest list at this stage," the couple's spokesperson said. "All we are saying is that it will be a small intimate affair with close family and others, which include godparents."
It is thought that senior members of the royal family and the Middletons will be present at the ceremony which will take place at the Chapel Royal at St James's Palace.
Shortly after George's grand entrance into the world, aides said there was no royal protocol that the Duke and Duchess of Cambridge had to follow for the occasion.
In the past, royal babies including Prince William have been christened by the Archbishop of Canterbury in the Music Room of Buckingham Palace, with only close family, godparents and friends in attendance.
The last member of the family to be christened in St James's Palace was William's cousin Princess Beatrice in December 1988.
No details have yet been announced of George's godparents, but it's thought he will have six.
Among those tipped for the honour are Pippa Middleton, Prince Harry, William's best friend Thomas van Straubenzee, former private secretary Jamie Lowther-Pinkerton, ex-nanny Tiggy Pettifer née Legge-Bourke, and Kate's Marlborough friend Alicia Fox-Pitt.
Hugh van Cutsem - whose father recently passed away - is also in the running. His daughter Grace was a bridesmaid when the Duke and Duchess tied the knot, and the little girl is also William's goddaughter, making it all the more likely he'll return the favour.
William's good friend Guy Pelly recently denied rumours that he had been chosen as one of George's godparents.
The nightclub entrepreneur explained to the Daily Mail, "People have been coming up to me and shaking my hand offering their congratulations all week.
"It's been weird. I've had to explain to everyone that I am not going to be a godfather. They have got it all wrong.
"I spoke to William yesterday about it and he confirmed I am not going to be one. And I want to set the record straight.
Guy continued, "William wasn't annoyed about people getting it wrong, just quite matter-of-fact that it should be put right."