Mortal Engines is a 2018 post-apocalyptic steampunk film directed by Christian Rivers from a screenplay by Fran Walsh, Philippa Boyens, and Peter Jackson, based on the 2001 novel of the same name by Philip Reeve. It stars Hera Hilmar, Robert Sheehan, Hugo Weaving, Jihae, Ronan Raftery, Leila George, Patrick Malahide, and Stephen Lang. An American–New Zealand co-production, the film is set in a post-apocalyptic world where entire cities have been mounted on wheels and motorised, and practice municipal Darwinism; its movie universe is different from that of the books.

Jackson purchased the rights to the book in 2009, but the film languished for several years before being officially announced in 2016. Jackson picked Rivers, who won an Academy Award for Best Visual Effects for his work on Jackson's King Kong, to make his feature-length directorial debut with the project, and also brought on several members of his production teams from The Lord of the Rings and The Hobbit film trilogies. Filming took place from April to July 2017 in New Zealand.

Mortal Engines had its world premiere on November 27, 2018, in London, was theatrically released in Australia and New Zealand on December 6, 2018, and in the United States on December 14, 2018. The film received negative reviews from critics, with some praising the visual effects and score, but with most criticizing the direction, screenplay and "lack of personality". It is one of the biggest box office bombs of all time, grossing $83.7 million against a production budget of $100–150 million and losing the studio an estimated $175 million.