Even after having lived the hardscrabble life of a missionary's daughter all her life and seen the loss of both parents, young Pollyanna Whittier (Hayley Mills) refuses to be depressed. Instead, she must be glad about anything she can think of, and it's paid off big time. Now, however, she must go to live with her cold, spinsterish Aunt Polly Harrington (Jane Wyman) in a town inhibited by embittered, unfriendly souls. Can she use her glad game to win over everyone and transform the town?