Live Free or Die Hard, released as Die Hard 4.0 outside the United States, is a 2007 action film, and the fourth installment in the Die Hard series. The film was directed by Len Wiseman and stars Bruce Willis as John McClane, the protagonist of the first three films. Other cast members included Justin Long, Timothy Olyphant, Mary Elizabeth Winstead, and Maggie Q. The storyline takes place 19 years after the first film, and sees McClane face a gang of cyber terrorists. The film was based on the 1997 article "A Farewell to Arms" written for Wired magazine by John Carlin. The film's North American release date was June 27, 2007.

After the project was initially stalled due to the September 11, 2001 attacks, production eventually began, and the film's title was switched several times. A variety of visual effects were used for action sequences, even though Wiseman and Willis stated that they wanted to limit the amount of CGI in the film. In separate incidents during filming, both Willis and his stunt double were injured. Unlike the prior three films in the series, the US rating was PG-13 rather than R, thus toning down the language and violence by great lengths when compared to the first three films in the series. The original, uncensored version of Live Free or Die Hard was made available for the DVD release.

Live Free or Die Hard received generally positive reviews, earning a 80% approval rating on Rotten Tomatoes and 69/100 from Metacritic and had total international box office gross receipts of $383.1 million. For the DVD release, 20th Century Fox pioneered a new kind of DRM that tries to weaken the incentives for consumers to learn how to rip discs by offering them a downloadable version with studio-imposed restrictions. The score for the film was released on July 2, 2007 and a video game has been proposed for the Xbox 360.