Mary Nash was an American actress.

The Philadelphia Story is a 1940 American romantic comedy film starring Cary Grant, Katharine Hepburn, James Stewart and Ruth Hussey. Directed by George Cukor, the film is based on the 1939 Broadway play of the same name by Philip Barry about a socialite whose wedding plans are complicated by the simultaneous arrival of her ex-husband and a tabloid magazine journalist. The socialite, played by Hepburn in both productions, was inspired by Helen Hope Montgomery Scott (1904–1995), a Philadelphia heiress who had married Barry's friend.