A test screening is a preview screening of a movie conducted before its general release, in order to gauge audience reaction. Preview audiences are selected to obtain a cross-section of the population, and are usually asked to complete a questionnaire or provide feedback in some other form.

Feedback from a test screening may be used to improve, or at least alter, the movie before it is released. This may be as simple as changing the title of the film (as in the case of the film that became Licence to Kill), or it may be more substantial. Cases exist of test screenings prompting filmmakers to completely change the ending of a movie (by having a character die who would have survived, or vice versa, for instance); Pretty in Pink is an example of this.

It has been suggested that the usual practice of testing the movie with an audience representing the general public may be counterproductive in some cases. If a film's appeal is only for a particular section of the population, comments from viewers outside the target audience may prompt filmmakers to make changes that alienate the target audience without significantly broadening the film's appeal. The expression "dumbing down" often enters the conversation at this point. An example of a "dumbed down" film would be The Lord of the Rings.

Test screening is also used as a tool in the making of television programmes. Test screenings may be used before a series debuts, to help fine-tune the concept (as was famously done with Sesame Street, leading to a larger role for the Muppets), or to pre-test specific episodes (an extreme case, the Australian children's series Play School reportedly tests every one of its episodes with a preview audience in the target preschool demographic, rejecting any that elicits signs of boredom).