George Banks is an ordinary, middle-class man whose 21-year-old daughter, Annie, has decided to marry a man from an upper-class family, but George can't think of what life would be like without her. He becomes slightly insane, but his wife, Nina, tries to make him happy for Annie, but when the wedding takes place at their home and a foreign wedding planner takes over the ceremony, George must try to handle the fact that people grow up.