Buckingham Palace said in a statement: "Archie Harrison Mountbatten-Windsor will be christened in a small private ceremony by the Archbishop of Canterbury in the Private Chapel at Windsor Castle on Saturday 6th July.
"The Duke and Duchess of Sussex look forward to sharing some images taken on the day by photographer Chris Allerton.
"The godparents, in keeping with their wishes, will remain private."
Despite this, Sunrise's royal expert Robert Jobson expects Harry will choose his cousin Zara and her rugby player husband Mike Tindall, while Meghan could nominate her stylist best friend Jessica Mulroney.
Hello! Magazine picked a selection of Harry and Meghan's celebrity friends as likely candidates, including George and Amal Clooney and Serena Williams and her husband Alexis Ohanian.
New Idea understands that a host of senior members of the royal family are expected to attend, as well as American-born Meghan's mother Doria Ragland who is expected to travel from California for her grandson's big day.
Archie Harrison was born on May 6 this year.