A 19-year-old Kate first caught Prince William's eye when she strutted her stuff on the university catwalk eight years ago in the dress by designer Charlotte Todd.
Charlotte, who created the dress for a mere £30 while studying at the University of the West of England in 2000, has been told it's now worth £10,000 since the couple's engagement - an amount that is likely to increase to £100,000 if she becomes Queen.
Two years later, St. Andrew's University asked to borrow it for a fundraising fashion show, where Kate brought it to life on the catwalk.
Charlotte told the Daily Mail:"The dress is part of fashion history - the moment William could first have fallen in love with Kate - and that made me really proud.
"She looked fabulous, and I think she could become a style icon like Princess Diana."
But, despite its high value, Charlotte says she won't part with it. "The only person I'd probably give it to is her - maybe in exchange for a wedding invitation."
We like your style!