Britain's royal palace says Prince Louis will be christened July 9 by Archbishop of Canterbury Justin Welby.
The third son of Prince William and his wife Kate, Duchess of Cambridge was born April 23 and is fifth in line to the throne.
Kensington Palace said Wednesday that Louis will be baptized in a private service at the Chapel Royal at St. James's Palace in London.
He will wear a cream lace and satin gown also used for the christenings of his elder siblings, Prince George and Princess Charlotte. It is a replica of a christening gown made for Queen Victoria's eldest daughter in 1841 and used for generations of royal babies until it wore out.