Sierra Sue is a 1941 American Western film directed by William Morgan and starring Gene Autry, Smiley Burnette, and Fay McKenzie. Written by Earl Felton and Julian Zimet, the film is about a government inspector investigating a poisonous weed that is destroying the rangeland supporting the area's cattle. The inspector must persuade the ranchers to reject a plan to burn the land and support a new process of chemical spraying from an airplane. The film features the popular Autry songs "Be Honest With Me", "Ridin' the Range", and the title track.