Blair Witch is an 2016 American found footage supernatural horror film directed by Adam Wingard and written by Simon Barrett. It is the third film in the Blair Witch series and a direct sequel to the 1999 film The Blair Witch Project. It ignores the events of its 2000 non found footage follow-up Book of Shadows: Blair Witch 2, whose events comprise a film within a film. It stars James Allen McCune, Callie Hernandez, Brandon Scott, Corbin Reid, Valorie Curry and Wes Robinson. The film follows a group of college students and their local guides who venture into the Black Hills Forest in Maryland to uncover the mysteries surrounding the prior disappearance of Heather Donahue, the sister of one of the characters.

Development of the film began in 2009, when creators of the franchise Daniel Myrick and Eduardo Sánchez announced their intent to produce a third Blair Witch film. It was to be a sequel to the first film, whose cast it could feature in some context, and not refer to any of the events from Book of Shadows. In 2011, Sánchez remarked that further development on a sequel depended on getting Lionsgate Films to approve the idea and for his and Myrick's schedule to match up. The film went into development hell, and later the script was thrown aside. In 2013, a third Blair Witch film was again in talks, with Wingard and Barrett being hired to work on a new script. Initially, the film's connection to the Blair Witch franchise was kept secret, having been shot under the fake title The Woods. Its true title was revealed at the 2016 San Diego Comic-Con.

Blair Witch premiered at San Diego Comic-Con on July 22, 2016, and was screened at the Toronto International Film Festival on September 11, before being theatrically released on September 16, by Lionsgate. The film received mixed reviews, with critics noting it as an improvement on Book of Shadows, although they criticized its writing and special effects. The film grossed $45.2 million against a budget of $5 million.