The couple will be married at St Mark’s church in the Berkshire village of Englefield, near where Miss Middleton grew up, with the reception being held in her parents’ garden.
The Duke and Duchess of Cambridge will be among guests at the wedding, with Prince George and Princess Charlotte acting as page boy and bridesmaid.
Kate confessed to a guest at a Buckingham Palace garden party on Tuesday that she is worried about how her children will behave on the big day.
After chatting to the Duchess, Andrew Bates said: “She said that they were all really looking forward to her sister’s wedding at the weekend, but she was a bit worried about how her children might behave.
“She said she was hopeful that they would be good, but you never know at that age.”
Prince George will be following in his father’s footsteps, as the Duke of Cambridge served as a page boy at the Duke and Duchess of York’s wedding in 1986.
Prince William wore a fetching sailor’s outfit and a straw boater for the occasion, but it is not yet known what the young royals will wear for their aunt’s wedding.
Prince Harry is also invited to the ceremony along with his girlfriend, American actress Meghan Markle.
If Ms Markle does attend, it will be the first time she will be seen in public with other members of the Royal Family.
Mr Matthews’ younger brother, reality TV star Spencer Matthews, will also be among the guests at the congregation and is thought likely to serve as his brother’s best man.
The engaged couple have hired public relations expert Jo Milloy to provide advice in the run-up to the big day.
Ms Milloy has worked for David and Victoria Beckham and has been described in the media as a PR guru responsible for Brand Beckham.
In the garden of the Middleton parents’ home, a large marquee, appearing to be made out of glass, has been put up so guests will not get wet if it rains.
Miss Middleton gained widespread public attention when she appeared in a figure-hugging dress as her sister’s maid of honour at the Royal wedding in 2011.
She has since written a number of newspaper and magazine columns as well as a book on party planning.
She got engaged to Mr Matthews last summer during a trip to the Lake District.
Pippa is widely expected to follow in her sister’s footsteps and wear two wedding dresses, one for the ceremony and one for the evening festivities.
It has not yet been revealed who has designed her outfits, but fashion experts have suggested several possible designers including Amanda Wakeley, Jenny Packham, Oscar De La Renta, Giles Deacon and Alexander McQueen.
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