Doctor John Dolittle is an eccentric, kind-hearted English physician who transitions to veterinary medicine after his human patients abandon his messy, animal-filled clinic. He learns to speak animal languages, fundamentally shifting his worldview and allowing him to treat creatures with deep empathy. His altruistic nature drives him to sacrifice his financial stability to care for both local pets and exotic wildlife.

Polynesia is a wise, aged parrot who serves as Doctor Dolittle's primary teacher in the art of interspecies communication. Originally from Africa, she possesses a strategic mind and devises clever plans to protect the group from human threats. Her bilingual abilities make her an indispensable asset to the doctor's practice and travel plans.

Chee-Chee is an agile monkey who finds a safe haven in Puddleby after suffering mistreatment. He acts as the catalyst for the main expedition by delivering urgent news about a deadly epidemic affecting his cousins in Africa. His knowledge of jungle environments proves vital for the traveling animal crew.

The King of Jolliginki is a defensive monarch who attempts to protect his lands by imprisoning Doctor Dolittle. His deep mistrust stems from prior exploitation by European visitors who ravaged his environment and slaughtered local wildlife. He views all white outsiders through the lens of these past betrayals.

Dab-Dab is a practical duck who assumes the role of housekeeper after human staff abandon the doctor. She brings organizational skills to the chaotic household and manages daily logistics for the extensive animal family. Her sharp eye for detail keeps the group focused during their various misadventures.

Jip is a brave dog with an extraordinary sense of smell. He transforms from a standard pet to a specialized operative, securing a vital role within the traveling crew by using his olfactory abilities to detect approaching danger and track specific scents.

Gub-Gub is an endearing but clumsy pig who brings lightheartedness to the group. He exhibits a childlike wonder and a strong affinity for food, occasionally leading the crew into trouble through his lack of discipline. Despite his shortcomings, he remains a cherished member of the doctor's makeshift family.

Too-Too is an exceptionally perceptive owl whose acute hearing provides crucial intelligence for the group. He acts as an advisor to the doctor, detecting faint sounds that warn of hidden individuals or concealed information. His sensory skills consistently aid the group in mysterious situations.

Prince Bumpo is the son of the King of Jolliginki. He encounters the captive animal crew and catches the attention of Polynesia, who views him as a potential asset for securing the group's freedom.

The Fisherman is a resilient sailor with red hair and an anchor tattoo who refuses to join a band of pirates. He faces severe consequences and marooning for defying the pirate captain, relying on his young nephew and the doctor's crew for a chance at freedom.

Tommy is an eight-year-old boy who suffers capture during a fishing trip with his uncle. He represents innocence trapped in a hostile environment, relying on Doctor Dolittle and his unusual animal companions for comfort and safety.

Sarah Dolittle is the practical sister of Doctor Dolittle. She values local reputation and financial stability, growing increasingly frustrated by the untidy, animal-filled state of their home. She eventually issues an ultimatum regarding the wildlife, prioritizing conventional human society over her brother's eccentric veterinary mission.

The Leader of the Lions is a proud predator who initially refuses to nurse the sick monkey population. He views the medical task as beneath his dignity, reflecting hierarchical prejudices within the animal kingdom until his own family circumstances force a change of perspective.

Ben Ali, styling himself as the Dragon of Barbary, is a ruthless pirate leader operating along the North African coast. He steals cargo, ransoms crews, and targets Doctor Dolittle's expedition for profit, making specific and violent threats against the doctor's animal companions.