The exhibition includes gowns such as the ice blue satin gown she wore to win Best Actress at the Oscars and the dusky pink taffeta dress by Helen Rose that she wore for during her civil ceremony to Prince Rainier III of Monaco.
On Thursday, Grace's son Prince Albert of Monaco and his wife Princess Charlene were spotted opening the exhibition, entitled From Philadelphia to Monaco: Grace Kelly – Beyond the Icon.
Beautiful in a burgundy halter neck dress, Charlene was the epitome of Hollywood glamour – a look Albert's mother would no doubt have been proud of.
The blonde royal was seen looking closely at the pictures and outfits on display as the pair toured the exhibition at James Mitchner Library in Doylestown, Pennsylvania.
Prince Albert was thrilled to open the collection – for which he filmed a video tribute to the Hollywood princess-turned real life royal.
"I'm deeply touched by your interest in my mother and her rich legacy,' he says in the video, which will be shown to the public attending the retrospective.
"Most of the world knows my mother first as a Hollywood film actress, then as the princess of Monaco.
"She was indeed a beautiful and talented woman and a fashion icon but that is just the surface of her life."