The Duke and Duchess of Cambridge's youngest child will be baptised at the Chapel Royal at St James' Palace in London on July 9.
The Queen is head of the Church of England and Louis' father William will one day take on this role when he becomes king.
Prince Louis will be three months old, which is how old Prince George was for his Christening, while Princess Charlotte was two months old at the time of hers at St. Mary Magdalene Church, Sandringham.
Louis was born at the private Lindo Wing of St Mary's Hospital in Paddington, London, on St George's Day, weighing 8lb 7oz.
The baptism will be a private affair, lasting around 30 minutes.
Jessica Bridge of Ladbrokes told the Express: 'As with George and Charlotte, the Duke and Duchess chose close and trusted friends and aides, rather than immediate family members, and the odds suggest that will be the same with little Prince Louis'. "The Cambridges are well aware of the media spotlight on and interest in their family - we saw that with the recent photos of Prince George and Princess Charlotte playing at the polo match".
The Queen, Prince Charles and the Duchess of Cornwall are set to attend.
Just like his brother and sister, Prince Louis will be christened not long after being born.