Peter Cullen, 85, the Voice Behind Optimus Prime, Dies — His Brother’s 6 Words That Shaped the Iconic Role

Peter Cullen, the voice behind Optimus Prime for more than four decades, has died at 85. As fans remember his legendary career, a deeply personal story about his brother reveals the six words that helped shape the voice of one of animation’s most beloved heroes.

Peter Cullen, the voice behind one of animation’s most recognizable heroes, has died — and while the news of his passing has prompted an outpouring of tributes, the story behind the voice of Optimus Prime is every bit as remarkable as the character himself.

It goes back to a difficult period in Cullen’s life, a 1984 audition and a piece of advice from his Vietnam veteran brother that would ultimately help define a cultural icon.

Peter Cullen attends an event in April 2026, just months before his death at age 85. The veteran voice actor returned to Optimus Prime for the 2007 Transformers movie after roughly two decades away, helping carry the character from the original animated series into the blockbuster film franchise. | Source: Getty Images

The Voice Behind Optimus Prime Has Died

Cullen, best known for voicing Optimus Prime throughout the Transformers franchise, died Wednesday, August 26, at his home in Los Angeles. He was 85.

His agent confirmed the news to TMZ, while his family said he passed away peacefully, surrounded by his loving family – and held in the hearts of his many friends and countless fans worldwide.

His family asks that you honor his remarkable legacy by serving your communities and leading others with compassion, integrity, and loyalty, the statement read further.

Peter Cullen joins Optimus Prime at a 2014 handprint ceremony outside the TCL Chinese Theatre in Hollywood, where the character was honored with a tradition usually reserved for Hollywood stars. The tribute underscored how closely Cullen had become linked to the Autobot leader after voicing him across the Transformers franchise. | Source: Getty Images

The cause of death has not been disclosed, leaving that part of the story unanswered as fans and colleagues remember the Canadian-born performer. They ended their statement with a phrase that would take on an especially poignant meaning given the story Cullen had told for years about the creation of Optimus Prime.

A Career That Went Far Beyond One Autobot

Cullen became synonymous with Optimus Prime after first taking on the role in the original 1984-87 syndicated Transformers animated series. When the franchise moved to the big screen decades later, director Michael Bay brought Cullen back for the 2007 Transformers movie, starring Shia LaBeouf.

In a 2007 interview also reported by The Hollywood Reporter, Cullen recalled that returning to the character after roughly two decades felt surprisingly natural. He compared it to slipping into a pair of very comfortable shoes that you haven’t worn for a while.

Peter Cullen attends the premiere of the first live-action Transformers movie in 2007, the year he returned to the role of Optimus Prime after roughly two decades away. His comeback came as the franchise made the leap from its beloved animated roots to the big screen. | Source: Getty Images

The character’s defining qualities had also remained clear to him: strength, courage, integrity, honor, passion, and leadership. Those qualities would prove particularly important because Cullen had never imagined Optimus as simply a loud or stereotypically tough hero.

In fact, the voice came from somewhere much more personal.

The Story Behind That Legendary Voice

Before Cullen became Optimus Prime, he was simply an actor heading into an audition in 1984. He had been told he was auditioning for a hero — and that the hero happened to be a truck.

Cullen later explained that he was living with his brother Larry at the time. Larry was a decorated Marine Corps captain who had served in Vietnam and had earned a Bronze Star with V and two Purple Hearts.

Peter Cullen leaves his handprints and footprints in cement at the TCL Chinese Theatre in Hollywood in 2014, marking a rare honor that recognized the man behind Optimus Prime rather than the character alone. The ceremony came as Cullen’s voice had become inseparable from the heroic Autobot leader. | Source: Getty Images

The brothers were extremely close, despite being just 13 months apart. As Cullen recalled in a TFcon interview, Larry would take an interest in where his younger brother was going each day.

When Cullen explained that he was auditioning to play a hero truck, Larry’s demeanor changed.

Peter, if you’re gonna be a hero, be a real hero; don’t be a Hollywood hero type with all the BS and all the yelling and screaming and trying to be tough, be strong enough to be gentle.

Those six highlighted words would stay with Cullen.

The Advice Became the Character

Rather than inventing an exaggerated superhero voice, Cullen decided to draw directly from his brother. He listened to Larry’s voice, watched his demeanor, and focused on the quiet authority that came from someone who had actually experienced war.

Cullen explained that he used his brother’s voice and advisory manner when reading the lines during his audition. The approach worked. Cullen felt he had nailed the character because he was not merely performing a fictional hero — he was drawing from someone he already considered heroic.

He ultimately landed the role of Optimus Prime, as well as the Autobot weapons specialist Ironhide. Years later, Cullen explained that the connection to Larry remained at the heart of the performance. In comments reported by The Hollywood Reporter, Cullen said of his brother, When he came home, I could see a change. He was quieter, and he was a man and a superhero to me.

He added, I watched him and listened to him. I’d never had an opportunity to do a superhero, and when that came, [that voice] just came right out of me, and I sounded like Optimus.

Fans Almost Lost Optimus for Good

Cullen’s connection to the character became even more significant after Optimus Prime was killed in The Transformers: The Movie in 1986. At the time, Cullen was genuinely devastated. He later recalled reading the script with Frank Welker, who voiced Megatron, and discovering that his character was being killed.

Jeez, I’m getting whacked here. Frank, you’re killing me. The decision produced an enormous reaction from fans, something Cullen did not immediately realize. The backlash eventually helped bring both the character and Cullen back for the 1987 straight-to-video The Transformers: The Return of Optimus Prime.

Peter Cullen and Frank Welker attend the Transformers: The Ride-3D grand opening at Universal Orlando in 2013. The longtime collaborators had already given audiences two of the franchise’s most recognizable voices, with Welker playing Megatron opposite Cullen’s Optimus Prime. | Source: Getty Images

By the time Michael Bay revived the franchise for the 2007 live-action movie, bringing Cullen back was considered an obvious choice. The actor told IGN that the filmmakers understood how important the original voice was to fans, saying the producers’ thermometer was the fan base.

Optimus Wasn’t Cullen’s Only Iconic Voice

While Optimus Prime became Cullen’s signature role, his career stretched across decades and included an unusually wide range of characters. He voiced Eeyore in Winnie the Pooh, Monterey Jack in Chip ’n Dale Rescue Rangers, and K.A.R.R. on Knight Rider.

He also voiced Mario in the 1980s animated Donkey Kong series and played King Kong in the 1976 movie remake. And then there was the Predator. Cullen supplied the terrifying clicking sounds of the creature in Arnold Schwarzenegger’s 1987 film Predator, creating the unsettling vocal effect from the creature’s appearance and movements.

In a 2018 account, Cullen recalled he was coughing up blood after working long hours on another project when his agent urged him to audition.

Read also

• New Aragorn? Viggo Mortensen’s Only Son Sports a Beard and Long Hair as Fans Call Him the ‘Spitting Image’ of His Dad – Photos
• Tim Curry’s Memoir Confession: The Two Women He Said Left Him ‘Untethered’ — and Why He Never Got Over It
• The Life of NASCAR Champion Kyle Busch, Including Details About His Health – Photos

He insisted on seeing what the creature looked like because, as he explained, If I can’t see the character, I don’t know what I’m gonna do. I have to have something to relate to, to put myself inside of. After seeing the creature, he described its face and tentacles as resembling an upside-down horseshoe crab dying in the sun on a beach when I was a kid.

From that image came the unsettling sounds that became part of the Predator’s identity. And Cullen’s contribution did not simply disappear with the 1987 film. The final designed Predator click sound for Prey was also based on the sound he had helped create, extending a piece of his work into a much later chapter of the franchise.

That instinct — finding something tangible to connect with — was also central to how he created Optimus Prime.

A Voice That Became a Legacy

Cullen once told NPR that he discovered his gift for voices as a child while living on a farm. He could imitate cows, calves, chickens, and dogs, and remembered realizing that the animals would react when he made certain sounds.

His career eventually took him from Canadian theater and radio to Hollywood, where he worked on The Smothers Brothers Comedy Hour and The Sonny & Cher Comedy Hour before becoming one of the most recognizable voice actors in the business.

Yet Optimus Prime remained his favorite. Cullen said the character was at the top of his list because of the positive effect he had on so many people.

I’m overwhelmed by that, and I’m very proud of that fact — that I did something in my life that made a difference — and it’s an honor, and I’m very grateful for it.

That sentiment makes his family’s final words especially fitting.