Lacey Chabert as Lisa Stuarts (new character who becomes Leo’s love interest, joins the gang)
Tyrese Gibson as Robert Epps
John Turturro as Seymour Simmons
Kevin Dunn as Ronald Witwicky
Julie White as Judy Witwicky
Glenn Morshower as General Morshower
Peter Cullen as Optimus Prime. Combines with Jetfire’s parts to become Jetpower Optimus Prime
Kevin Michael Richardson as Ultra Magnus - Autobot Mobile Missile Launcher, serves as Second-in-command of the Autobots
Lisa Ortiz(Voice of Amy Rose) as Chromia (joins Sam, Hot Rod and the gang after rescuing Mikaela from Cyclonus and Blitzwing)
Jason Griffith(Voice of Sonic the Hedgehog) as Hot Rod/Rodimus Prime - Chevrolet Corvette, later Chevrolet Avalanche (will serve as Lisa Stuart’s car and guardian and help Optimus restore the Dynasty of Primes)
Jason Griffith as Jetstorm; (another SR-71 Blackbird and brother of Jetfire who joins Optimus after learning that his brother is dead.)
Michael Wright as Trailbreaker, an autobot Saturn VUE who serves as an autobot sergant.
Warpath, an autobot triple-changer with a tank mode and rail gun mode.
Joseph Gordon-Levitt - Wheeljack (Autobot Gears Specialists, arrives on Earth with Ultra Magnus, transforms into a fighter jet)
Josh Keaton (Voice of The Spectacular Spiderman) as Prowl (Autobot Police Dodge Durango SUV)
Jason Griffith as Springer (Triple Changer - Car to chopper to robot)
Dinobots: A group of Seekers that take on the form of several dinosaurs they see in the American Museum of Natural History. These five take over Skids and Mudflap’s role as comic relief. Like Jetfire and Wheelie, these 5 originally served the Decepticons, but chose to side with the Autobots, joining Sam, Hot Rod and the others on their quest.
David Kaye as Grimlock - Dinobot leader - T-rex
Slag - Triceratops
Sludge - Apatosaurus
Snarl - Stegosaurus
Swoop - Pteranodon
Kevin Michael Richardson as Omega Supreme - Guardian of Cybertron - transforms into a giant spaceship, big enough to house several Autobots.
Aerialbots: A younger group of Seekers who hid on Earth for 200 years before Sector Seven was founded. All 6 combine to form Superion, voiced by Lance Henriksen.
James Avery(Fresh Prince of Bel-Air) as Silverbolt - Leader of the Aerialbots
3 siblings - two Aerialbot brothers who joke around and bicker with each other like Skids & Mudflap and Jetfire & Jetstorm, whilst the sister gets annoyed by her brothers bickering.
Will Smith (Fresh Prince of Bel-Air) as Metalhawk
Alfonso Ribeiro(Fresh Prince of Bel-Air) as Slingshot
Tara Strong as Terradive (primary female Aerialbot who is smart enough to know the odds of winning against the Decepticons)
Ben Diskin(Voice of Venom) as Sky Shadow - silent ninja of the Aerialbots
Airazor - Aerialbot technition
Metroplex or Fortress Maximus - City fortress / giant warship as bigger than Omega Supreme, big enough for all the Autobots and their human allies.
Hugo Weaving as Megatron/Galvatron, the new official Decepticon leader who fled with Starscream in the last film refusing to surrender to the Autobots over the death of his master The Fallen.
Charlie Adler as Starscream, Decepticon Air Commander and close partner to Megatron
Frank Welker as Soundwave, Communications Specialist
Laserbeak, a minion of Soundwave that resembles a large condor
Jess Harnell as Barricade - serves as Prowl’s rival
Gary Sturgis (voice of Ebon) as Cyclonus
James Arnold Taylor as Scourge
Lex Lang as Shockwave, Megatron’s most loyal second-in-command
Matthew Wood (Voice of General Grevious) as Blitzwing, transforms into a X-29 jet and an assault tank
Astrotrain, a triple changer that transforms into a cybertronian shuttle and plane.
Combaticons: A group of Decepticons recruited by Starscream after Galvatron banishes/replaces him with Cyclonus. These 6 can combine into Bruticus, voiced by Tony Todd.
Michael Clarke Duncan as Onslaught - leader of the Combations
Vincent Tong(Voice of 2009 Mandarin) as Vortex, Decepticon UH-60 Blackhawk
Overkill, Decepticon AH-64 attack chopper
Grey DeLisle as Strika - primary female Combaticon
Kevin Grevioux as Treadshot - M1 Abrams tank that will replace Brawl
Blast Off - B-2 Spirit who forms the back of Bruticus
Matthew Wood will provide vocal sound effects for the Sweeps
Leonard Nimoy as Unicron, a large and enormous robot with a planet mode the size of an asteroid.