Humans are at war with the Transformers, and Optimus Prime is gone. Transformers: The Last Knight (Transformers 5) The key to saving the future lies buried in the secrets of the past and the hidden history of Transformers on Earth. Now, it’s up to the unlikely alliance of inventor Cade Yeager, Bumblebee, an English lord and an Oxford professor to save the world. Transformers: The Last Knight (Transformers 5)
- Mark Wahlberg as Cade Yeager, a single father and inventor, who helped the Autobots during the events of Age of Extinction. Transformers: The Last Knight (Transformers 5)
- Josh Duhamel as Col. William Lennox, a former NEST commander and U.S. Army Ranger captain, who partnered with the Autobots prior to the events of Age of Extinction, and now a U.S. Army Colonel and reluctant member of the Transformers Reaction Force (TRF).
- Stanley Tucci as Merlin, King Arthur’s wizard and Viviane’s ancestor. Tucci was originally reported to be reprising his role as Joshua Joyce from Age of Extinction.
- Anthony Hopkins as Sir Edmund Burton, 12th Earl of Folgan, an astronomer and historian who knows about the history of the Transformers on Earth. Transformers: The Last Knight (Transformers 5)
- Laura Haddock as Viviane Wembly, a Professor of English Literature at the University of Oxford and a polo player, who turns out to be a descendant of Merlin. Minti Gorne portrays a younger Viviane.
- Isabela Moner as Izabella, a street-wise tomboy who was orphaned with Sqweeks and Canopy, her only friends, until meeting Cade. Transformers: The Last Knight (Transformers 5)
- Jerrod Carmichael as Jimmy, a young man from South Dakota whom Cade hired through a want ad.
- Santiago Cabrera as Santos, a former Delta Force operative and commander of the TRF, who seeks to eradicate every Transformer and their human allies regardless of faction.
- John Turturro as Seymour Simmons, a former government agent with Sector Seven and NEST turned successful writer who hides out in Cuba, and was allied with the Autobots prior to the events of Age of Extinction.
- Glenn Morshower as General Morshower, the director of NEST in Revenge of the Fallen and Dark of the Moon who now supervises TRF operations.
- Liam Garrigan as King Arthur, the legendary knight who first fought with the Knights of Iacon. Liam Garrigan previously portrayed a version of King Arthur in Once Upon a Time.