An orphaned young girl named Heidi (Shirley Temple) lives happily with her grouchy but gentle grandfather, Adolph (Jean Hersholt) in the Swiss Alps. When she's stolen by her ruthless aunt, Dete (Mady Christians), and sold as a servant to the wealthy Herr Sesemann (Sidney Blackmer), Adolph embarks on a journey to find his granddaughter. Meanwhile, Heidi keeps her spirits high and befriends Sesemann's crippled daughter, Klara (Marcia Mae Jones), but longs to return home.