Yuri Lowenthal
Ben Tennyson (voice) (20 eps)
Ashley Johnson
Gwen Tennyson (voice) (20 eps)
Greg Cipes
Kevin Levin (voice) (20 eps)
Dee Bradley Baker
Humungosaur (voice) (20 eps)
John DiMaggio
Young Four Arms / Aggregor (voice) (18 eps)
Paul Eiding
Max Tennyson / Guard #1 / Guard #2 (voice) (5 eps)
Vyvan Pham
Julie Yamamoto / Computer Voice (voice) (4 eps)
Scott Menville
Jimmy Jones (voice) (3 eps)
Peter MacNicol
Oliver / Forever Knight #1 (voice) (2 eps)
Fred Tatasciore
Quince / Robot Guard (voice) (2 eps)
Kevin Michael Richardson
Kwarrel (voice) (2 eps)
David McCallum
Professor Paradox (voice) (2 eps)
Alexander Polinsky
Argit (voice) (2 eps)
Kari Wahlgren
Charmcaster (voice) (2 eps)
Wil Wheaton
Mike Morningstar / Darkstar (voice) (2 eps)
Zeno Robinson
Alan Albright / Heatblast (voice) (2 eps)
Chris Pratt
Cooper (voice) (1 eps)
Beth Littleford
Sandra Tennyson (voice) (1 eps)
J.K. Simmons
Magister Gilhil / Plumber (voice) (1 eps)
Greg Ellis
Dagonet / Reporter Chet Rigby (voice) (1 eps)
Nicholas Guest
Simons / Worker / Guest (voice) (1 eps)
Matt Levin
Cash (voice) (1 eps)
Tara Strong
Serena / Young Ben Tennyson (voice) (1 eps)
Xander Berkeley
Warden Morgg / Trukk (voice) (1 eps)
Rob Paulsen
Technician / Rhomboid Vreedle / Engineer #2 (voice) (1 eps)
Dwight Schultz
Dr. Animo / Teacher #2 (voice) (1 eps)
Christopher McDonald
Captain Nemesis (voice) (1 eps)
Tara Platt
Jennifer Nocturne (voice) (1 eps)
Jim Piddock
King Urien / Color Commentator / Chair Umpire (voice) (1 eps)
Jeff Bennett
Pops Vreedle / Jailer (voice) (1 eps)
Sean Donnellan
Cameraman / Thug / Tech (voice) (1 eps)