Tess Newall wore the dress at her wedding last year and it was made by her great, great grandmother in 1870. She handed it to Kleen cleaners in Edinburgh but the firm soon went into administration.
She posted on Facebook asking for help locating the dress and her plea has received more than 155,000 shares.
Because of the antique design of the dress, Ms Newall believes it could be on sale at a vintage wedding fair or shop.
Her plea on social media attracted the attention of Bridebook, a wedding planning website, who are coordinating a search on her behalf and have offered to buy a replacement dress for whoever has the dress.
"I'm overwhelmed by the heart-warming response and how kind everyone has been in helping to search for the dress - ordinary people, the press and the wedding industry," Ms Newall told The Independent.
"I really believe we will find the dress thanks to the enormous support I'm getting and I'm so grateful!
"My great-great-granny would be overwhelmed by this global attention of her beautiful dress I am sure," she added.