Stanley T. Banks (Spencer Tracy) is a securely middle-class lawyer whose daughter Kay (Elizabeth Taylor) announces that she's going to marry her beau Buckley Dunstan (Don Taylor). From that point on, everything in Stanley's life is turned upside down. His wife Ellie (Joan Bennett) wants Kay to have the kind of formal wedding that she and Stanley never had, and between meeting his soon-to-be in-laws, the socially prominent Herbert and Doris Dunstan (Moroni Olsen and Billie Burke), his man-to-man talk with the groom, hosting the engagement party, financing the increasingly lavish wedding, and wondering if Kay and Buckley will resolve their differences before arriving at the altar, Stanley barely has time to deal with his own considerable anxieties about his advancing age and how his "little girl" became a grown woman.