When a royal bride gets married, it's quite customary for her wedding dress to go on exhibition shortly after the wedding day.
Meghan Markle and Prince Harry's wedding outfits went on display at Windsor Castle in later 2018, and after that they were replaced in the exhibition by Princess Eugenie's wedding dress.
This also happened with the late Princess Diana's wedding gown. It was displayed for a while at Althorp House, where she is buried, and it went on tour for a few years during the Diana: A Celebration exhibit, though it generally wasn't part of the displays for long.
However, you're not likely to see the dress IRL anytime soon, as it is now privately owned by her sons, Prince William and Prince Harry. This happened in 2014, as Princess Diana asked for her belongings to be given to them when they both turned 30.
Eleri Lynn, former curator of the exhibition Diana: Her Fashion Story, held at Kensington Palace in 2018, revealed this in a conversation with historian and Historic Royal Palaces' joint chief curator Lucy Worsley.
Asked if we would ever see the dress again, she replied it was now 'part of the private collection of the Dukes of Sussex and Cambridge'.
As such, it is unlikely to be displayed, unless the Princes choose otherwise, but it's easy to imagine them wanting to keep this particular outfit private.
