Peter Cullen as Optimus Prime (voice)

Frank Welker as Megatron / Terrorcon (voice)

Steve Blum as Starscream / Darksteel (voice)

Jeffrey Combs as Ratchet (voice)

Will Friedle as Bumblebee (voice)

James Horan as Wheeljack (voice)

Michael Ironside as Ultra Magnus (voice)

Peter Mensah as Predaking (voice)

Sumalee Montano as Arcee (voice)

John Noble as Unicron (voice)

Daran Norris as Knock Out (voice)

Nolan North as Smokescreen / Skylynx (voice)

Kevin Michael Richardson as Bulkhead (voice)

David Sobolov as Shockwave (voice)