Lacey Chabert as Eliza Thornberry (voice)

Tom Kane as Darwin (voice)

Cree Summer as Phaedra (voice)

Tim Curry as Nigel Thornberry (voice)

Lynn Redgrave as Cordelia Thornberry (voice)

Danielle Harris as Debbie Thornberry (voice)

Flea as Donnie Thornberry (voice)

Crystal Scales as Cheetah Cubs (voice)

Kimberly Brooks as Tally (Cheetah Cub) (voice)

Alfre Woodard as Akela (Cheetah Mother) (voice)

Brock Peters as Jomo (voice)

Melissa Greenspan as Sarah Wellington (voice)

Alexandra Boyd as Victoria (voice)

Moira Quirk as Jane (voice)

Jodi Carlisle as Marianne Thornberry (voice)

Mae Whitman as Schoolgirl (voice)

Marisa Tomei as Bree Blackburn (voice)

Rupert Everett as Sloan Blackburn (voice)

Earl Boen as Gorilla (voice)

Jack Angel as Poachers (voice)

Bob Bergen as Poachers (voice)

Bill Farmer as Poachers (voice)

Kevin Michael Richardson as Shaman Mnyambo (voice)