Green Lantern is a 2011 American superhero film based on the DC Comics character of the same name. The film stars Ryan Reynolds, Blake Lively, Peter Sarsgaard, Mark Strong, Angela Bassett, and Tim Robbins, with Martin Campbell directing a script by Greg Berlanti and comic book writers Michael Green and Marc Guggenheim that was subsequently rewritten by Michael Goldenberg. This was the first DC film since Catwoman (2004) not to be involved with Legendary Pictures. The film tells the story of Hal Jordan, a test pilot who is selected to become the first human member of an intergalactic police force called the Green Lantern Corps; he is given a ring that grants him superpowers and must confront Parallax, a being who threatens to upset the balance of power in the universe, while a new threat rises back on Earth.

The film first entered development in 1997; progress remained stalled until Berlanti was hired to write and direct in October 2007. Martin Campbell was brought on board in February 2009 after Berlanti was forced to vacate the director's position. Most of the live-action actors were cast between July 2009 and February 2010, and filming took place from March to August 2010 in Louisiana. The film was converted to 3D during its post-production stage.

Green Lantern was released in the United States on June 17, 2011, by Warner Bros. Pictures. The film received generally negative reviews from critics for its script, tone, visual effects, and unfaithfulness to the source material, and underperformed at the box office, grossing $220 million against a production budget of $200 million. It was also originally intended to start a film franchise based on DC characters. However, due to the film's critical and commercial disappointment, Warner Bros. scrapped plans for a sequel, opting instead to use Man of Steel (2013) as the official start of the DC Extended Universe, two years after Green Lantern's release.