War for the Planet of the Apes is a 2017 American science fiction action film directed by Matt Reeves, who co-wrote it with Mark Bomback. The sequel to Dawn of the Planet of the Apes (2014), it is the third installment in the Planet of the Apes reboot film series and the ninth film overall. It stars Andy Serkis as Caesar, alongside Woody Harrelson and Steve Zahn. The film takes place two years after the events of Dawn and follows the conflict between apes and humans as it has escalated into full war, while Caesar sets out to avenge those he has lost.

Development for War for the Planet of the Apes began in January 2014, after 20th Century Fox viewed Reeves's cut of its predecessor; his return was soon confirmed, along with Bomback's. A conditional 2016 release date was announced in May 2015, which led to a closer and faster pre-production relationship between writer and director. The film bears similarities to Battle for the Planet of the Apes (1973), with emphasis on the effect of psychosocial development and interaction of apes and humans. Casting began in August 2015 and finished that October, with principal photography commencing soon thereafter and concluding in March 2016, with filming locations including Lower Mainland and the Kananaskis Range.

War for the Planet of the Apes premiered on July 10, 2017, at the SVA Theatre in New York City, and was theatrically released worldwide by 20th Century Fox on July 14. It received critical acclaim and was a commercial success, grossing over $490 million, and received numerous awards and nominations, including nominations for Best Visual Effects and Best Special Visual Effects at the 90th Academy Awards and 71st British Academy Film Awards, respectively. A standalone sequel, Kingdom of the Planet of the Apes, was released in 2024.