Terminator Salvation is a 2009 American military science fiction action film that is the fourth installment of the Terminator franchise, serving as a sequel to Terminator 3: Rise of the Machines (2003). It is directed by McG and written by John Brancato and Michael Ferris. It is the only Terminator film to date not to feature Arnold Schwarzenegger, though his likeness briefly appears digitally. Instead, it stars Christian Bale and Sam Worthington with Anton Yelchin, Moon Bloodgood, Bryce Dallas Howard, Common, Michael Ironside, and Helena Bonham Carter in supporting roles. In a departure from the previous installments, Salvation is a post-apocalyptic film set in the year 2018. It focuses on the war between Skynet's machine network and humanity, as the remnants of the world's militaries have united to form the Resistance to fight against Skynet. Bale portrays John Connor, a Resistance fighter and central character, while Worthington portrays cyborg Marcus Wright. Yelchin plays a young Kyle Reese, a character first introduced in The Terminator (1984), and the film depicts the origins of the T-800 Terminator.

After troubled pre-production, with the Halcyon Company acquiring the rights from Andrew G. Vajna and Mario Kassar, and with several writers working on the screenplay, filming began in May 2008 in New Mexico, and ran for 77 days.

Terminator Salvation was released on May 21, 2009, by Warner Bros. Pictures in the United States, and by Sony Pictures Releasing under its Columbia Pictures label internationally, and grossed over $371.4 million worldwide but received mixed-to-negative reviews. While originally intended to be the first installment of a second Terminator trilogy, these plans were canceled following the Halcyon Company filing for bankruptcy after the film's release. The franchise rights were sold in 2012 to Annapurna Pictures, resulting in Terminator Genisys, a reboot of the series, being released in 2015 with Schwarzenegger reprising his role.