The Duke and Duchess of Sussex made a secret visit to Queen Elizabeth II on 14 April.
A representative for the couple confirmed to the BBC that the couple made a stop at Windsor Castle on their way to the Invictus Games in The Netherlands.
The trip marks the first time Prince Harry and Meghan have returned to the U.K. together since they stepped down as senior members of the royal family and moved to America in early 2020.
However, Harry has returned on his own previously - once for his grandfather Prince Philip's funeral and for an event commemorating his late mother Diana, Princess of Wales.
The pair did not bring their children - Archie, two, and Lilibet, 10 months - citing increased risk without police protection.
Harry and Meghan lost their police guard when they departed their roles within the royal family.
The 37-year-old is currently in legal proceedings against the British government, having challenged Home Office officials' decision to refuse him to pay for police protection in a personal capacity.