John Travolta - Bolt (voice)

Miley Cyrus - Penny (voice)
Susie Essman - Mittens (voice)

Mark Walton - Rhino (voice)

Malcolm McDowell - Dr. Calico (voice)

James Lipton - The Director (voice)

Greg Germann - The Agent (voice)

Diedrich Bader - Veteran Cat (voice)
Nick Swardson - Blake (voice)

J.P. Manoux - Tom (voice)
Dan Fogelman - Billy (voice)
Kari Wahlgren - Mindy (voice)

Chloe Moretz - Young Penny (voice)
Randy Savage - Thug (voice)

Ronn Moss - Dr. Forrester (voice)

Grey DeLisle - Penny's Mom (voice)

Sean Donnellan - Penny's TV Dad (voice)

Lino DiSalvo - Vinnie (voice)
Todd Cummings - Joey (voice)
Tim Mertens - Bobby (voice)
Kelly Hoover - Ester (voice) (as Kellie Hoover)

Brian Stepanek - Martin (voice)
Jeff Bennett - Lloyd (voice)
Daran Norris - Louie (voice)
John Di Maggio - Saul (voice)
Jenny Lewis - Assistant Director (voice)