Full cast of Ben 10: Ultimate Alien

Yuri Lowenthal

Ben Tennyson (voice)

52 episodes

Ashley Johnson

Gwen Tennyson (voice)

52 episodes

Greg Cipes

Kevin Levin (voice)

52 episodes

Dee Bradley Baker

Humungosaur (voice)

52 episodes

John DiMaggio

Aggregor (voice) / Vulkanus / Rath (voice) / Diagon (voice) / Will Harangue / Octagon Vreedle (voice) / Rath / Conduit Edwards / Diagon (voice) / Swamps / Rath Albedo / V.O. Announcer (voice) / Conduit Edwards / Carnival Barker (voice) / Foreverduke838 (voice) / Addwaitya / Aggregor / Faint Voice (voice) / Audience Member / Will Harangue / Rath (voice) / Magister Coronach / Octagon Vreedle (voice) / Plumber / Aggregor (voice) / Young Four Arms / Aggregor (voice) / Forever Knight #2 / Rath / TV Reporter (voice) / Spellbinder / Addwaitya / Diagon (voice) / Will Harangue / Rath (voice) / Trash Monster / Colonel Rozum / Additional Voices (voice) / Ultimate Aggregor / Volann Commander (voice)

30 episodes

Jeff Bennett

Azmuth (voice) / Pops Vreedle / Jailer (voice) / Major Domo / Hugh (voice) / Magister Labrid / Major General (voice)

11 episodes

Vyvan Pham

Julie Yamamoto / Computer Voice (voice) / Julie Yamamoto / Ship (voice) / Julie Yamamoto (voice) / Mrs. Jones (voice) / Erin / Julie Yamamoto (voice)

11 episodes

Paul Eiding

Max Tennyson / Guard #1 / Guard #2 (voice)

7 episodes

Peter Renaday

Sir George (voice) / Old George (voice)

6 episodes

Scott Menville

Jimmy Jones (voice) / J.T. (voice) / Jimmy / J.T. / Pilot 2 (voice)

5 episodes

Juliet Landau

Natalie Tennyson / Melinda (voice) / Verdona Tennyson / Waitress (voice) / Fritz (voice)

5 episodes

James Remar

Vilgax (voice)

5 episodes

Alexander Polinsky

Argit (voice)

4 episodes

Kari Wahlgren

Charmcaster (voice)

4 episodes

Fred Tatasciore

Staradisimus / Forever Knight #3 (voice) / Quince / Robot Guard (voice) / Foreman / Surgeon / Hammer (voice)

3 episodes

Rob Paulsen

Baz-El / Forever Knight #1 / Churl #4 (voice) / Rhomboid Vreedle / Magister Patelliday (voice) / Technician / Rhomboid Vreedle / Engineer #2 (voice)

3 episodes

David McCallum

Professor Paradox (voice)

3 episodes

Dwight Schultz

Dr. Animo / Teacher #2 (voice) / Sheriff / Dr. Animo (voice)

3 episodes

Wil Wheaton

Mike Morningstar / Darkstar (voice)

3 episodes

Patrick Cavanaugh

Winston / Esoterica / Additional Voices (voice)

3 episodes

Chris Pratt

Cooper (voice)

2 episodes

Greg Ellis

Dagonet / Reporter Chet Rigby (voice) / Prince Gyula / Cyborg #2 (voice)

2 episodes

Peter MacNicol

Oliver / Forever Knight #1 (voice)

2 episodes

Kevin Michael Richardson

Magister Pyke (voice) / Kwarrel (voice)

2 episodes

Jason Marsden

Antonio (voice) / Young Max Tennyson (voice)

2 episodes

James Arnold Taylor

Announcer / Fake Vilgax / Fridge (voice) / Plumber Officer / Brannigan / Kolar (voice)

2 episodes

Molly C. Quinn

Eunice / Computer (voice)

2 episodes

Tia Texada

Elena Validus (voice)

2 episodes

Robin Atkin Downes

Sir Cyrus / Additional Voices (voice)

2 episodes

Richard Doyle

Driscoll / Additional Voices (voice)

2 episodes

Christopher McDonald

Captain Nemesis (voice)

2 episodes

Tara Platt

Jennifer Nocturne (voice)

2 episodes

Zeno Robinson

Alan Albright / Heatblast (voice)

2 episodes

Sean Donnellan

Ben 10,000 / Eon (voice) / Cameraman / Thug / Tech (voice)

2 episodes

Powers Boothe

Sunder (voice)

1 episode

Peter Stormare

King Xarion / King Viktor (voice)

1 episode

Beth Littleford

Sandra Tennyson (voice)

1 episode

J.K. Simmons

Magister Gilhil / Plumber (voice)

1 episode

Nicholas Guest

Simons / Worker / Guest (voice)

1 episode

Matt Levin

Cash (voice)

1 episode

Tara Strong

Serena / Young Ben Tennyson (voice)

1 episode

Xander Berkeley

Warden Morgg / Trukk (voice)

1 episode

Brian George

Victor Valadis / Janitor (voice)

1 episode

Miguel Ferrer

Magister Hulka / Alpha #4 (voice)

1 episode

Charlie Schlatter

Tack / Plumber (voice)

1 episode

Olivia Hack

Emily (voice)

1 episode

Adam Wylie

Pierce / Forever Knight #3 (voice)

1 episode

Diedrich Bader

Simian (voice)

1 episode

Jon Polito

Mizaru (voice)

1 episode

Keone Young

Julie's Dad / Repair Man / Cop (voice)

1 episode

Yeni Alvarez

Dr. Borges (voice)

1 episode

Bill Mumy

Agent Bryson (voice)

1 episode

Vicki Lewis

Agent Locke (voice)

1 episode

Diane Delano

Ma Vreedle / Pretty Boy Vreedle (voice)

1 episode

Khary Payton

Hex (voice)

1 episode

Marianne Muellerleile

Maureen (voice)

1 episode

Danny Jacobs

Captain / Police Dispatch / Dr. Pervis (voice)

1 episode

Jim Piddock

King Urien / Color Commentator / Chair Umpire (voice)

1 episode

Tress MacNeille

Zennith (voice)

1 episode