Optimus Prime's calm voice was modelled on a Marine brother home from Vietnam
When Peter Cullen read for a heroic truck-robot in Burbank, his older brother Larry told him real heroes are tough enough to be gentle. Cullen channelled that quiet strength into Optimus Prime, and the character's death in a 1986 film left children leaving cinemas in tears.
Cullen was born in Montreal on July 28, 1941, to American parents of Irish descent: a paper-company founder from Boston and a mother trained at the American Academy of Dramatic Arts. Summers on an aunt's farm in New York gave him an early hobby of imitating the animals, and he mimicked his teachers too. After school in Kingston, Ontario, he joined the first class to graduate from the National Theatre School of Canada in 1963.
Serious repertory theatre bored him, so he spent a year pumping petrol in Montreal before drifting into comic revues. There he met the American comedian Ted Zeigler, and the pair became a double act on Montreal children's television, playing among other things a French-Canadian astronaut called Commander Bi Bi Latuque. In 1971 a failed NBC pilot brought him to Los Angeles, where he worked as announcer and performer on The Sonny and Cher Comedy Hour until 1974. An agent, Steve Tisherman, later persuaded him to drop on-camera work entirely for voice acting. One persistent myth credits him as announcer on The Smothers Brothers Comedy Hour, but that job belonged to Roger Carroll.
Tisherman phoned with double good news: Cullen had landed both Optimus Prime and Ironhide. He said Prime was his favourite role, and he only grasped its popularity after the character was killed off in the 1986 animated film, since the studio had never passed on children's letters. The outcry forced writers to bring the leader back, first for a single episode and then permanently for the show's last five.
He returned to the role in 2007 for the first live-action Transformers film and kept it through the sequels, with his last performance as the character in 2026. His other voices ranged from the melancholy donkey Eeyore to the snarls of the Predator. He received a lifetime achievement award at the Children's and Family Emmys in 2023 and died on August 26, 2026.
Source: Peter Cullen
