This is a very rare picture indeed ........one of filmstar , Grace Kelly wearing a bathing suit . Not that Miss Kelly is allergic to bathing suits or swimming , but she seldom poses for publicity stills in beach attire . The bride - to - be of Monaco ' s Prince Rainier III is wearing a Grecian - style bathing suit . The picture was taken between scenes on the set of ' High Society ' . Miss Kelly is scheduled to sail for Monaco 4 April . 1956