The family event is sure to make for some memorable moments, especially with his older siblings Prince George and Princess Charlotte, who regularly steal the show with their cuteness.
On Wednesday, Kensington Palace announced that Prince Louis will be baptised on 9 July.
It will be held by the Most Reverend Justin Welby, who christened Louis' older brother George, and older sister Charlotte.
Louis, the Queen's great-grandson, is fifth in line to the throne.
His next public appearance is likely to be his christening, for which no public date has been announced.
Prince William and Kate have sent individual thank you notes to well-wishers to mark Prince Louis' birth.
And the christening itself is quite the family tradition, Royal Central U.K. notes, adding Prince Louis will also wear a replica of the now-famous Honiton lace christening gown.
Princess Charlotte was christened on 5 July 2015 at St Mary Magdalene Church in Sandringham. Not only has he performed Charlotte and George's christenings but he also officiated Harry and Meghan's wedding vows back in May.
The mother-of-three is taking time off from royal engagements in order to spend time with her sons and Princess Charlotte, three. It will be a small gathering similar to George's christening, to which only 22 guests were invited. Get HELLO! Canada, PEOPLE, Vanity Fair and over 100 more of the world's best magazines for one low monthly price at Texture by Next Issue.