Geppetto, an elderly woodcarver, lives alone in a modest workshop crafting toys and clockwork. His solitary existence transforms when he carves a pinewood puppet, Pinocchio, treating him as a son instantly. Kind-hearted and humble, he lacks biological family but shows paternal affection toward his pets, Figaro the kitten and Cleo the goldfish, confiding in them. His selfless wish upon a star for Pinocchio to become a real boy is granted by the Blue Fairy, recognizing his lifelong dedication to bringing joy. Though startled by Pinocchio's sudden sentience, Geppetto embraces him immediately as his child, offering care and guidance.

His personality blends whimsical playfulness with practicality. He demonstrates playful mischief, encouraging Pinocchio to tease Figaro, yet exhibits profound devotion. When Pinocchio fails to return from school, Geppetto searches tirelessly through storms and perilous places, ultimately sailing into the ocean. This quest leads to his capture by the massive whale Monstro. Trapped inside the whale for an extended time, he resourcefully fishes for food and sustains hope. Reuniting with Pinocchio inside Monstro, his priority is their bond, not questioning the puppet's donkey transformations, though he expresses concern about the physical changes.

During their escape, Monstro destroys their raft; Geppetto nearly drowns but is saved by Pinocchio. Later, he mourns Pinocchio's apparent death after their escape, unaware the Blue Fairy revives him as a human boy. His grief turns to overwhelming joy upon discovering Pinocchio's transformation and restoration.

Geppetto's background includes poverty and sacrifice, such as selling his only coat to buy Pinocchio's schoolbooks. Alternate adaptations expand his character: one live-action version reveals a deceased biological son, deepening his investment in Pinocchio. Another reimagines him as Papa Carlo, an impoverished organ grinder given a sentient log by a drunken carpenter. Extended accounts of his time in Monstro depict him creating art from salvaged materials to preserve sanity while ruminating on guilt and paternal failures.

Physically, Geppetto is slender with white hair, a mustache, blue eyes, and a pinkish nose. He typically wears spectacles, a vest, breeches, and buckled shoes; his attire varies, including work aprons, nightgowns, or traveling coats during his searches.

Adaptations further explore his parental challenges. In one musical, he struggles with Pinocchio's disobedience and naivety, leading to conflicts with puppeteer Stromboli over a binding contract. His journey to Pleasure Island reveals the consequences of the puppet's choices, culminating in another encounter with Monstro and a contractual resolution demanding sacrifice.

Geppetto's core remains consistent: a creator whose love and regret define his fatherhood, enduring isolation and danger for his son. His arc develops from a solitary craftsman to a resilient, devoted parent, emphasizing sacrifice and redemption.