Transformers: The Last Knight is a 2017 American science fiction action film based on the Transformers toy line. It is the fifth installment of the live-action Transformers film series and the sequel to Age of Extinction (2014). Like its predecessors, the film is directed by Michael Bay and features Mark Wahlberg reprising his role from Age of Extinction, while Josh Duhamel, John Turturro, and Glenn Morshower reprise their roles from the first three films, as well as Laura Haddock, Isabela Moner, Jerrod Carmichael, Santiago Cabrera, and Anthony Hopkins all joining the cast. Returning Transformers include Optimus Prime, Bumblebee, Hound, Drift, Crosshairs, Wheelie, Megatron, and Barricade.
The film premiered at Odeon Leicester Square in London on June 18, 2017, and was theatrically released in the United States on June 21, 2017, by Paramount Pictures. The film was panned by critics and is the worst-reviewed film of the Transformers series. Criticism focused on its runtime, direction, narrative, lack of character development, screenplay, cinematography, and frequent format changes throughout. At the 38th Golden Raspberry Awards, it was nominated for ten awards, including Worst Picture, Worst Director, and Worst Actor for Wahlberg. The film became the franchise's second box-office bomb following the 1986 animated film The Transformers: The Movie (1986), grossing $605 million worldwide against a production budget between $217–260 million, with an estimated loss of over $100 million for both Paramount and Hasbro after marketing and distribution costs. A spin-off film titled Bumblebee, with Bay as producer was released on December 21, 2018 to critical and financial success.