"I Whistle a Happy Tune" is a show tune from the 1951 Rodgers and Hammerstein musical, The King and I. It is sung by the Governess Anna Leonowens (originally played on Broadway by Gertrude Lawrence) to her son Louis after the curtain rises on Act One of the musical, to persuade him not to be afraid as they arrive in Siam to serve the King. In the 1956 film version, it was sung by Deborah Kerr (dubbed by Marni Nixon) and Rex Thompson. In the 1999 animated film version, it was sung by Christiane Noll, Adam Wylie, Charles Clark, Jeff Gunn, David Joyce and Larry Kenton.