Prince Louis will be christened later in a private ceremony in the Chapel Royal at St James’s Palace.
The 11-week-old will be baptised by the Archbishop of Canterbury, the Most Reverend Justin Welby, in the palace’s Chapel Royal.
It will be the first time the Duke and Duchess of Cambridge and their three children have been seen together.
Louis is set to wear the same christening gown used by his siblings, Prince George and Princess Charlotte.
The cream lace and white satin robe is a replica of the robe made for Queen Victoria’s eldest daughter in 1841, which is now too delicate to be worn. The new version was made by the Queen’s dresser, Angela Kelly.
Louis’ godparents, who will be announced on the day, will take part in the private 40-minute traditional religious ceremony, which begins at 1600 BST.
According to tradition, water from the River Jordan is set to be used for Louis’s christening.
While they have not been named, William’s private secretary Miguel Head – who leaves the post this month – is the bookies’ favourite to be among the godparents.
The Cambridges have previously chosen close friends and confidantes for the role.
Kensington Palace has not released the guest list, but newlyweds the Duke and Duchess of Sussex are expected to attend, along with Kate’s pregnant sister Pippa Middleton and their brother James Middleton.
Meghan was christened and confirmed in the oak-panelled Chapel Royal by the archbishop, who also married her and Harry in May.
Louis Arthur Charles weighed 8lb 7oz when he was born in the private Lindo Wing of St Mary’s Hospital in Paddington, London, on 23 April. He is fifth in line to the throne.
His elder brother George was also christened in the Chapel Royal, but sister Charlotte was baptised at the Church of St Mary Magdalene in Sandringham.
News Source BBCNews