Unknown is a 2011 action-thriller film directed by Jaume Collet-Serra and starring Liam Neeson, Diane Kruger, January Jones, Aidan Quinn, Bruno Ganz, and Frank Langella. The film, produced by Joel Silver, Leonard Goldberg and Andrew Rona, is based on the 2003 French novel by Didier Van Cauwelaert published in English as Out of My Head which was adapted as the film's screenplay by Oliver Butcher and Stephen Cornwell. The narrative centers around a professor who wakes up from a four-day long coma and sets out to prove his identity after no one recognizes him, including his own wife, and another man claims to be him.

Jaume Collet-Serra is a Spanish-American film director and producer. He directed the horror films House of Wax (2005), Orphan (2009), and The Shallows (2016), as well as the Liam Neeson-led thriller films Unknown (2011), Non-Stop (2014), Run All Night (2015), and The Commuter (2018). Collet-Serra also directed the Dwayne Johnson-led films, Jungle Cruise (2021), based on the eponymous theme park attraction from Disney, and Black Adam (2022), based on the comic book character of the same name from DC.