Myles Jeffrey as T.J. Detweiler (voice)

Pamela Adlon as Spinelli (voice)

Dabney Coleman as Principal Prickley (voice)

Ashley Johnson as Gretchen Grundler (voice)

Allyce Beasley as Miss Grotke (voice)

Rickey D'Shon Collins as Vince LaSalle (voice)

Jason Davis as Mikey Blumberg (voice)

Courtland Mead as Gus Griswald (voice)

Andrew Lawrence as Younger T.J. (voice)

Lane Toran as King Bob (voice)

Klee Bragger as Digger Sam (voice)

April Winchell as Miss Finster (voice)

Rachel Crane as Ashley Q (voice)

Ross Malinger as Older T.J. (voice)

Danny Cooksey as (voice)

Jane Curtin as (voice)

Aria Noelle Curzon as Cornchip Girl (voice)

E. G. Daily as Digger #1 (voice)

Miles Marsico as (voice)

Anndi McAfee as Ashley A (voice)

Sam McMurray as Lt. Griswald (voice)

Ryan O'Donohue as Digger Dave / Randall (voice)

Patricia Renna as (voice)

Justin Shenkarow as Gelman (voice)

Michael Shulman as Francis the Hustler Kid (voice)

Francesca Marie Smith as Upside-Down Girl / Ashley T / Swinger Girl (voice)

Aaron Spann as (voice)

Kath Soucie as Hector / Cindy / Gus's Mom (voice)

Tara Strong as Spinelli's Doll (voice)

Erik von Detten as Erwin Lawson (voice)

David Berry as (voice)