Chris Rock
Osmosis Jones (voice)
Laurence Fishburne
Thrax (voice)
David Hyde Pierce
Drix (voice)
Brandy Norwood
Leah (voice)
William Shatner
Mayor Phlegmming (voice)
Ron Howard
Tom Colonic (voice)
Mickie McGowan
Additional Character Voice (voice)
Elena Franklin
Shane Detorre
Uncle Kracker
Kidney Rock (voice)
Carlos Alazraqui
Additional Character Voices (voice)
Rodger Bumpass
Additional Character Voices (voice)
Richard Steven Horvitz
Additional Character Voices (voice)
Danny Mann
Additional Character Voices (voice)
Mickie McGowan
Additional Character Voices (voice)
Jonathan Adams
Additional Character Voices (voice)