Cloverfield is a 2008 American found footage monster horror film directed by Matt Reeves, produced by J. J. Abrams, and written by Drew Goddard. It stars Lizzy Caplan, Jessica Lucas, T.J. Miller (in his film debut), Michael Stahl-David, Mike Vogel, and Odette Yustman as six young New York City residents fleeing from a massive monster and various other smaller creatures that attack the entire city during a farewell party.

Development began when producer J. J. Abrams started conceptualizing a new monster and enlisted Neville Page to design the creature, called Clover. In February 2007, the project was secretly greenlit by Paramount Pictures and produced by Abrams's Bad Robot. Principal photography took place in Los Angeles and New York City in 2007. The project had several working titles, including Slusho, Cheese, and Greyshot. As part of a viral marketing campaign, a teaser trailer was released ahead of screenings of Transformers (2007) without a title. The final title was revealed in a second teaser trailer attached to screenings of Beowulf (2007). With limited pre-release details, it garnered online speculation, including forums and websites dedicated to uncovering hidden information about the film. Several tie-ins, including a prequel manga series, were released as part of the marketing campaign.

Cloverfield was released on January 18, 2008, and received generally positive reviews from critics, who praised Reeves's direction and the cinéma vérité style narrative. It earned $172 million worldwide at the box office against a $25 million budget. It is the first installment of the Cloverfield franchise, followed by 10 Cloverfield Lane in 2016 and The Cloverfield Paradox in 2018. A direct sequel is in development.