Prince George will be christened by the Archbishop of Canterbury next month at the Chapel Royal, St James's Palace, Kensington Palace announced today.
The Duke and Duchess of Cambridge's baby son will be baptised during the ceremony held on Wednesday, October 23 - just over three months since his birth.
Kensington Palace said "close members of both families" would attend but the names of senior guests would be released at a later date.
The Queen and Duke of Edinburgh are expected to attend the christening along with the Prince of Wales, who has become a grandfather for the first time, and the Duchess of Cornwall.
Kate's family - parents Carole and Michael Middleton and siblings Pippa and James - are likely to be invited along with the godparents who have not been publicly named.
The christening, conducted by the Most Rev Justin Welby, will be a private event with photographs released afterwards of William, Kate and their son, together with senior royals.
The ceremony is usually held at Buckingham Palace or at places of worship at Windsor Castle.
Princess Beatrice was the last royal baby to be christened at St James's Palace in December 1988.