Primer is a 2004 American independent psychological science fiction film about the accidental discovery of time travel. The film was written, directed, produced, edited and scored by Shane Carruth in his debut feature, who also stars with David Sullivan.

Shane Carruth is an American filmmaker, screenwriter, composer, and actor. He is the writer, director, and co-star of the prize-winning science-fiction film Primer (2004), which was his debut feature. His second film, Upstream Color (2013), was an experimental science-fiction film which he wrote, directed, produced, edited, designed, and starred in. He also composed the scores for both films. In recognition of Carruth's idiosyncratic and, at times, bizarre filmmaking technique, director Steven Soderbergh told Entertainment Weekly, "I view Shane as the illegitimate offspring of David Lynch and James Cameron."