I Am Number Four is a 2011 American science fiction action film directed by D. J. Caruso and starring Alex Pettyfer, Timothy Olyphant, Teresa Palmer, Dianna Agron, and Callan McAuliffe. The screenplay, by Alfred Gough, Miles Millar, and Marti Noxon, is based on the 2010 novel of the same name, one of the Lorien Legacies young adult science fiction novels. The film follows a teenage alien on Earth fleeing other aliens who are hunting him down.

Produced by Michael Bay, I Am Number Four was the first film production from DreamWorks Pictures to be released by Touchstone Pictures, as part of the studio's 2009 distribution deal with Walt Disney Studios Motion Pictures. The Hollywood Reporter estimated the budget to be between $50 million and $60 million. The film was released in both conventional and IMAX theatres on February 18, 2011, received generally negative reviews, but was a box-office success, grossing $149.9 million against a budget of $50‒59 million. All plans for a sequel were cancelled due to the film's poor performance. A reboot, produced by Neal H. Moritz, with Gough and Millar returning to write, is currently in the works.