A teaser trailer is a very short trailer (usually less than a minute) which offers a quick glance at an upcoming film. A teaser trailer is usually released before the full theatrical trailer of a film.

Teaser trailers are usually released for popular films to gain hype. Examples of teaser trailers for popular films include the Harry Potter films, The Lord of the Rings trilogy, the Spiderman films and many other eagerly awaited films.

Teaser trailers are usually released quite a while before the film is released. The full theatrical trailer is usually released after filming is complete, and a few months before the film is due to be released.

Often, with films such as Harry Potter and also with Star Wars, fans will pay admission fees just to see the teaser trailer and not the film that it is attached to. Some fans even leave the cinema after watching the teaser rather than stay to watch the film that the trailer is being shown with.