The American actress, 36, and Harry, 33, will tie the knot at St George's Chapel, Windsor Castle in May.
The chapel is much smaller than Westminster Abbey, where Harry's brother, Prince William, married Kate Middleton in 2011 and Prince Charles married Princess Diana, Harry and William's mother, in 1981.
The engagement of Prince Harry and Markle dominated newspaper front pages and morning news shows in Britain on Tuesday, as royal-watchers awaited the details.
The protestant actress will also be both baptised and confirmed ahead of the wedding.
The source turns out to have been right: The pair are now officially set to Wednesday at Windsor Castle in May, meaning they're staying far clear of Westminster Abbey, which is usually the royal wedding venue of choice, as evidenced most recently by Kate Middleton and Prince William.
The interior of St. George's Chapel at Windsor Castle.
It is not yet know how the public might be able to view either the wedding or the potential arrival of the bridal party at the chapel.
"Prince Harry and Ms Markle are leading the planning process for all aspects of the wedding".
Image Prince Harry and Meghan Markle will marry next May
The spokesman confirmed the American Ms Markle would begin the process of gaining United Kingdom citizenship, which was likely to take several years.
St. George's Chapel at Windsor Castle.
They will visit Nottingham, where Prince Harry started the Full Effect programme in 2014 through The Royal Foundation.
At the arts centre, they will join celebrations for World AIDS day hosted by the Terrence Higgins Trust.
"Bogart is now living with friends", Mr Knauf revealed.
Kensington Palace also revealed that Harry and Ms Markle will carry out their first official engagement together in Nottingham on Friday.
"In a happy moment in their lives, it means a great deal that so many people throughout the United Kingdom, the Commonwealth and around the world are celebrating with them".
Prince Charles will also be in Australia in early April to open the Commonwealth Games.More news: Small Business Saturday Has Big Impact On Communities