Transformers One is a 2024 American animated science fiction action film based on Hasbro's Transformers toy line. It was directed by Josh Cooley from a screenplay by Eric Pearson and the writing duo of Andrew Barrer and Gabriel Ferrari, based on a story by Barrer and Ferrari. The film features the voices of Chris Hemsworth, Brian Tyree Henry, Scarlett Johansson, Keegan-Michael Key, Steve Buscemi, Laurence Fishburne, and Jon Hamm. It is set on Cybertron, the home planet of the Transformers, and depicts the origins and early relationship of Optimus Prime and Megatron.

In March 2015, following the release of Transformers: Age of Extinction (2014), Paramount Pictures tasked Akiva Goldsman to set up a writers' room to create ideas for potential future Transformers films. By May 2015, Barrer and Ferrari had signed on as writers, and they came up with the idea of an animated prequel set on Cybertron. The film was announced in August 2017, and by April 2020, Cooley had been hired to direct. Animation services were provided by Industrial Light & Magic, and the design was primarily influenced by the Generation 1 era and Art Deco. The score was composed by Brian Tyler.

Transformers One premiered in Sydney, Australia, on September 11, 2024, and was released by Paramount Pictures in the United States on September 20. The film has received generally positive reviews from critics, who praised the story, animation, voice performances, and humor, but underperformed at the box office, grossing $128.9 million worldwide on a budget of $75–147 million.