After the service, the newly married couple will undertake a short ride in a carriage from the Royal Mews, out of Windsor Castle and on to part of the High Street.
State trumpeters from the Band of the Household Cavalry are also set to perform a fanfare during the ceremony, as well as musicians from the Royal Philharmonic Orchestra (RPO).
The Dean of Windsor, David Connor, will give the address at the wedding as well as officiate as the couple make their marriage vows.
Sophie Cabot started her bespoke cake design business in 2014 and was discovered by the royal couple through her involvement with The Duke of York's Pitch@Palace programme, where she supplied specially decorated bespoke biscuits.
And as more details emerge about Princess Eugenie's wedding, she and Meghan have an increasing amount of similarities when it comes to their big days.
Jack Brooksbank and Princess Eugenie.
Eugenie's sister Princess Beatrice is likely to be the maid of honour and the Duke and Duchess of Cambridge's children, Prince George and Princess Charlotte, are expected to be among the pageboys and bridesmaids. It has been described in a statement by Royal Communications as "a traditional cake with a modern feel".