Phil Lord
Principal Dr. Cinnamon J. Scudworth (voice) (20 eps)
Nicole Sullivan
Joan of Arc (voice) (16 eps)
Will Forte
Abe Lincoln / Narrator (voice) (13 eps)
Michael McDonald
Gandhi (voice) (13 eps)
Christa Miller
Cleopatra (voice) (13 eps)
Christopher Miller
JFK / Mr. Butlertron (voice) (13 eps)
Neil Flynn
Carl (voice) (12 eps)
Donald Faison
Toots / Wally (voice) (12 eps)
Andy Dick
Mr. Sheepman (voice) (7 eps)
Bill Lawrence
The Shadowy Figure (voice) (uncredited) (7 eps)
Debra Wilson
Reporter (voice) (4 eps)
Judah Miller
Scangrade (voice) (4 eps)
Murray Miller
Catherine the Great (voice) (4 eps)
Sarah Chalke
Marie Antoinette (voice) (3 eps)
Zach Braff
Paul Revere (voice) (2 eps)
Joe Flaherty
Abe’s Foster Dad (voice) (2 eps)
Marilyn Manson
Marilyn Manson (voice) (2 eps)
Michael J. Fox
Gandhi's Remaining Kidney (voice) (1 eps)
Mandy Moore
Mandy Moore (voice) (1 eps)
Luke Perry
Ponce de León (voice) (1 eps)
John C. McGinley
Creepy Trucker (voice) (1 eps)
Chris Berman
Chris Berman (voice) (1 eps)
John Stamos
John Stamos (voice) (1 eps)
Jack Black
Pusher / Larry Hardcore (voice) (1 eps)
Ashley Parker Angel
Ashley Parker Angel (voice) (1 eps)
Tom Green
Tom Green (voice) (1 eps)
Dan Patrick
Dan Patrick (voice) (1 eps)
Jeffrey Garcia
Jesús Cristo (voice) (1 eps)
Tommy Walter
Abandoned Pools (voice) (1 eps)