Before the Flood is a 2016 documentary film about climate change directed by Fisher Stevens. The film was produced as a collaboration between Stevens, Leonardo DiCaprio, James Packer, Brett Ratner, Trevor Davidoski, and Jennifer Davisson Killoran. Martin Scorsese is an executive producer.

The film covers effects of climate change in various regions of the world, and discusses climate change denial. Numerous public figures are interviewed in the documentary. To offset the carbon emissions of the production, the filmmakers paid a voluntary carbon tax. The soundtrack features compositions by Trent Reznor and Atticus Ross, Mogwai and Gustavo Santaolalla.

The film premiered at the Toronto International Film Festival in September 2016, and was released theatrically on October 21, before airing on the National Geographic Channel on October 30. As part of National Geographic's commitment to covering climate change, the documentary was made widely available and free of charge on various platforms. It received generally positive critical reviews.