Smell-O-Vision is a system that released odor during the projection of a film so that the viewer could "smell" what was happening in the movie. Created by Hans Laube, the technique made its only appearance in the 1960 film Scent of Mystery, produced by Mike Todd Jr., son of film producer Mike Todd. The process injected 30 odors into a movie theater's seats when triggered by the film's soundtrack.

Scent of Mystery is a 1960 American mystery film, the first to use the Smell-O-Vision system to release odors at points in the film's plot. It was the first film in which aromas were integral to the story, providing important details to the audience. It was produced by Mike Todd, Jr., who, in conjunction with his father Mike Todd, had produced such spectacles as This Is Cinerama and Around the World in Eighty Days.