The Wild Thornberrys

• Elizabeth "Eliza" Thornberry (voiced by Lacey Chabert) is a 12-year-old girl[1] and the youngest daughter of the Thornberrys. She has long red-orange hair that is usually worn in pigtails, and occasionally a ponytail, round eyeglasses, four big teeth connected by two braces, and freckles. She is able to communicate with animals, especially her chimpanzee sidekick Darwin. She must keep this gift secret or she will lose her powers (as revealed in the episode "Gift of Gab"). This happens during the film when Eliza reluctantly tells two poachers her secret in order to save Debbie. Luckily, after saving a herd of elephants from the same poachers later in the film, she is given her powers back. Despite her good intentions, she sometimes interferes with nature which causes more problems.[4]
• Sir Nigel Archibald Thornberry KBE (voiced by Tim Curry) is Eliza, Debbie, and Donnie's father and Marianne's husband. He is also the son of Radcliffe (also voiced by Curry) and Cordelia Thornberry (Lynn Redgrave), an aristocratic British couple. Born in the U.K. and having attended Harrow School near London, he travels around the world with his own family making wildlife documentaries. He is eccentric, enthusiastic, and cheerful even in the face of danger, and is also known for his exaggerated facial features and love of kippers which he offers frequently.
• Marianne Thornberry née Hunter (voiced by Jodi Carlisle) is Eliza, Debbie, and Donnie's mother and Nigel's wife. She is the daughter of Frank (Ed Asner) and Sophie Hunter (Betty White). She mentions that she attended the University of California, Berkeley and once competed in a rodeo as revealed in "Rebel Without a Trunk".
• Donald "Donnie" Thornberry (voiced by Flea) is a feral boy adopted by the Thornberrys, who speaks mostly in gibberish and (as revealed in the 4-part TV film, "The Wild Thornberrys: The Origin of Donnie") was raised by an orangutan in Borneo after his parents, Michael and Lisa, who were old friends of the Thornberrys, were killed by poachers.[4] Debbie is usually left taking care of Donnie and she's constantly trying to keep him in control. Donnie's age is 4, turning 5 in "The Origin of Donnie".[1]
• Deborah "Debbie" Thornberry (voiced by Danielle Harris) is a popular teenage girl, 16-years-old, and Eliza's sister. After the events of the movie, she becomes the only family member to know about Eliza's power but is warned that she will be turned into a baboon if she ever tells anyone. Debbie dresses in 1990s clothing and has a long swept hairstyle. Unlike Eliza, Debbie doesn't like traveling and wants nothing more than to live in civilization and make friends with people her own age.
• Darwin (voiced by Tom Kane) is the Thornberrys' pet chimpanzee and Eliza's best friend. He usually wears a tank top with horizontal blue and white stripes (used to be Debbie's lucky tank top) and blue shorts. He speaks with a distinct, upper-class British accent. Although he isn't too fond of Debbie, the two do share the same preference to living in civilization over the wilderness. He also acts as the voice of reason for Eliza whenever she tried to interfere in nature.
  • Kane also voices others.

• Kip O'Donnell (voiced by Keith Szarabajka) is a poacher and The Thornberrys’ sworn enemy who poaches and kidnaps animals from above it, with his partner Neil Biederman (voiced by Michael Jeter & replaced by Jerry Sroka). Whenever they aren't poaching animals, they are conducting schemes to make easy money. They would eventually be apprehended by the authorities after causing an oil spill while attempting to steal oil from an oil tanker in the episode "You Otter Know". Kip always refers to Eliza as "The Thornberry Girl".
• Tyler Tucker (voiced by Jonathan Taylor Thomas) is Eliza and Debbie's cousin. He is Marianne and Nigel's nephew through Marianne's sister Nancy Tucker née Hunter. He is a year older than Eliza but acts more immaturely than Eliza does. He doesn't really understand the dangers of living in the wild. He's a know-it-all but generally has a good head on his shoulders, and he cares about his cousins Debbie, Eliza, and Donnie. His parents are Dennis (voiced by Martin Mull) and Nancy Tucker (voiced by Mary Kay Place).
• Shane G. (voiced by Christopher Masterson) is a pop superstar who travels with the Thornberry Family for five episodes while they are filming in Alaska. The Foundation orders Nigel and Marianne to take him with the family to promote Wildlife preservation among young people and Shane's fans. Both Eliza and Debbie gain a crush on him, however Debbie loses interest when Shane shows to have more similarities with Eliza than herself.
• Santusa (voiced by Tia Texada) is a supremely annoying llama whom Eliza befriended in the Andes.
• Bim (voiced by Greg Ellis) is a Koala who has a British accent and befriended by Eliza, Darwin, & Donnie.
• Shango (voiced by Bradley Pierce) is an African Elephant who Eliza first met.
• Phaedra (voiced by Jane Wiedlin) is a female African Elephant who appears in the episode, "Forget Me Not", and who Eliza and Darwin were riding at the beginning of The Wild Thornberrys Movie.
• Zita (voiced by Andrea Thompson) is an African Elephant who was Rebecca's daughter and the mother of Shango, from the episode, Forget Me Not.
• Mali (voiced by Christina Pickles) is an African Elephant who was Zita's aunt and Phadera's daughter, when Eliza helps her.
• Juka (voiced by Marquise Wilson) is the leader of the Maasai legend between his wise Grandfather Makai (voiced by Courtney B. Vance & replaced by Steve Harris)
• Ben (voiced by David Gallagher) is a friend of Eliza's that Debbie teases her for having a crush on.
• Franz Fensterkopt (voiced by Bronson Pinchot)
• Dr. Jomo (voiced by Brock Peters) is a police officer who is a friend of Nigel Thornberry.
• Sri Mayasandra (voiced by Alan Henry Brown) is a scientist who had found Donnie in the TV special.
• Baru (voiced by Cara DeLizia) is a young Proboscis monkey who helps Eliza get back to her family, and his father, Baduk (voiced by Dwight Schultz).
• Lugan (voiced by Maureen Quinn), who was in the TV special.
• Saiful (voiced by Pamela Adlon), which was in the TV special. and Adlon voiced Tano, a Cheetah Cub who Eliza tries to help find and who she, Darwin and Donnie help try to find his mother in the episode, "Cheetahs Never Prosper".
• Shi Shou (voiced by Dionne Quan) is a baby panda, and Mei-Mei (voiced by Bai Ling), a mother panda.
• Conal (voiced by Michael Gough) is a golden eagle, and his wife Brianag (voiced by Laraine Newman).

• Arthur Burghardt as Big Buffalo, an African buffalo from the episode "The Kung and I" and a Rhino from the Pilot episode.
• Eartha Kitt and Sheryl Lee Ralph as the Lionesses in the episode "Flood Warning".
• Bill Cobbs as the Chief in the episode "Dinner with Darwin".
• Phil LaMarr, Jackie Harris and Paul Greenberg are Tuku, Pippo, Barno, the three mysterious prankster marmosets.
  • LaMarr also voices the Steamboat Captain in the episode "Matadi or Bust".
• David Huddleston as a sea tortoise in the episode "Gold Fever".
• David Eccles as a hippo in the episode "Matadi or Bust".
• Georg Stanford Brown as Kito, the leader jaguar from the episode "Temple of Eliza".
• Estelle Harris as Iguana/Turtle from the episode "Eliza-cology".
• Marabina Jaimes as Raamba, a jaguar who Eliza helped out of the pit in the episode "Temple of Eliza".
• Jeffrey Lincon and Sabrina Wiener as the jaguar cubs in the episode "Temple of Eliza".
• Erik Von Detten as an adolescent jaguar in the episode "Temple of Eliza"..
• Jeff Bennett as an officer in the episode "Vacant Lot".
• Jess Harnell as a tortoise and a marsh deer in the episode "Vacant Lot".
• Rosslynn Taylor Jordan as a tapir in the episode "Vacant Lot".
• Candi Milo as Emily, a female wombat from the episode, "Chew if by Sea".
  • Milo also voices a capybara, a parrot, a civet cat, a mousedeer, and others.
• Jeremy Sisto as the Radio announcer and the D.J.
• Jesse Corti as the two crocodiles in the episode "Only Child".
• Andrea Martin as Mother Condor from the episode "Flight of the Donnie".
• Susanna Voltaire, Russi Taylor, Melissa Fahn are Anna, Igna, and Katrina in "On the Right Track".
• William H. Macy as Skoot, a male reindeer who Eliza raced with in "On the Right Track".
• Bill Fagerbakke as Dank, a black reindeer who appeared in On the Right Track.
• Tom Kenny as Joey, a baby Kangaroo who Eliza babysits in Pal Joey.
• Gregg Berger and S. Scott Bullock are Lemke and Snaga, the Tasmanian devils in the episode "Pal Joey".
  • Berger also voices a lion and a warthog in the episode "Flood Warning". A water buffalo and a doctor in the episode "The Dragon and the Professor".
  • Bullock also voices a python and a forest hog
• Cree Summer as Rosie, a "teenage" Asian elephant in "Rebel Without a Trunk".
• Danny Cooksey as Wanuug, a polar bear who appeared in Polar Opposites.
• David Ogden Stiers as Karroo, an Aye-aye from "Luck Be an Aye-aye".
• Ron Fassler, Anne Lambton, & Jimmie Wood are Tak a little rat, Sheeba the eye patch wearing cat, & Bone, the three legged dog who helped Eliza find the Bangaboo in The Great Bangaboo.
• Marion Ross as Rebecca, an elephant whom Eliza saved in Forget Me Not. She was originally saved by Nigel from poachers many years ago. At the end of the episode, the elephant dies of natural causes which makes Eliza cry after she passes away and her daughter Zita takes over the herd.
• Robert Morse as Jake, a male tortoise who Eliza helped in Two's Company.
• Phyllis Diller as Samantha, a female tortoise who Eliza helped in Two's Company.
• Kelly McGillis & Peter Onorati are Winema and Pava, the leader Gray Wolves that appeared in the episode, Pack of Thornberrys.
• Chris Demetral as Mato, a Gray Wolf who appeared in the episode, Pack of Thornberrys.
• Bill Brochtrup as Collin, a Common dolphin who Eliza swam with in the episode, Hello, Dolphin!.
• Jane Goodall as Herself, appears in the episode, The Trouble with Darwin.
• Vicki Lewis as Weasel from the episode "Lost and Foundation"
• Pam Grier as Mother Springbok from the episode "Stick Your Neck Out"

Common Sense Media gave the series a rating of 5 stars, praising it for its ability to encourage young viewers to be empathetic toward animals, to want to find out about other cultures and ways of life, and to understand the vastness and diversity of the world.[23] Knight Ridder called the series "sympathetic".[24] The Native Voice complimented the series on its commitment to fun, adventure, detail, accuracy, and honesty.[25]