Full Cast — Ben 10: Ultimate Alien (2010–2012)

Yuri Lowenthal

Ben Tennyson (voice)

Ashley Johnson

Gwen Tennyson (voice)

Greg Cipes

Kevin Levin (voice)

Dee Bradley Baker

Humungosaur (voice)

John DiMaggio

Plumber / Aggregor (voice) / Swamps / Rath Albedo / V.O. Announcer (voice) / Ultimate Aggregor / Volann Commander (voice) / Forever Knight #2 / Rath / TV Reporter (voice) / Will Harangue / Octagon Vreedle (voice) / Magister Coronach / Octagon Vreedle (voice) / Will Harangue +25 more

Vyvan Pham

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

Jeff Bennett

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

Paul Eiding

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

Peter Renaday

Sir George (voice) / Old George (voice)

Scott Menville

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

Juliet Landau

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

James Remar

Vilgax (voice)

Alexander Polinsky

Argit (voice)

Kari Wahlgren

Charmcaster (voice)

Fred Tatasciore

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

Rob Paulsen

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

David McCallum

Professor Paradox (voice)

Dwight Schultz

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

Wil Wheaton

Mike Morningstar / Darkstar (voice)

Patrick Cavanaugh

Winston / Esoterica / Additional Voices (voice)

Chris Pratt

Cooper (voice)

Greg Ellis

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

Peter MacNicol

Oliver / Forever Knight #1 (voice)

Kevin Michael Richardson

Magister Pyke (voice) / Kwarrel (voice)

Jason Marsden

Young Max Tennyson (voice) / Antonio (voice)

James Arnold Taylor

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

Molly C. Quinn

Eunice / Computer (voice)

Tia Texada

Elena Validus (voice)

Robin Atkin Downes

Sir Cyrus / Additional Voices (voice)

Richard Doyle

Driscoll / Additional Voices (voice)

Christopher McDonald

Captain Nemesis (voice)

Tara Platt

Jennifer Nocturne (voice)

Zeno Robinson

Alan Albright / Heatblast (voice)

Sean Donnellan

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