Heidi is a five-year-old orphan girl sent to live with her reclusive grandfather in the Swiss Alps. She is optimistic, observant, and naturally empathetic to those around her. Her innocent, unsophisticated nature brings joy to her companions but later clashes with the rigid rules of city life when she relocates to Frankfurt.

Known to the villagers as "Uncle Alp," he is a reclusive man who lives in solitude on the mountain after suffering personal tragedies. He is a skilled carpenter and tends to his goats, relying on the natural environment for his daily needs. Despite his gruff exterior and the townspeople's fear of him, he shows immediate tenderness toward his young granddaughter.

Peter is a young goatherd who travels up the mountain daily to shepherd the villagers' flocks. He lives in a drafty, rundown cabin with his mother and blind grandmother. He acts as a guide to the mountains for his new friend, though he can be stubborn and sometimes struggles with jealousy regarding her attention.

The strict housekeeper who manages the Sesemann residence in Frankfurt. She enforces rigid rules and views children primarily as nuisances requiring discipline. She is easily horrified by animals, dirt, and unrefined behavior.

A twelve-year-old girl from a wealthy Frankfurt family who has a physical disability and uses a wheelchair. She is lonely and confined indoors due to her health and the city environment. She finds rural innocence charming and deeply values companionship.

Peter's elderly, blind grandmother who spends her days spinning wool in a dark, drafty cabin. Despite her poverty and physical limitations, she maintains strong moral resolve and spiritual devotion. She provides a sense of community for the mountain residents.

An ambitious working woman who assumed guardianship of her niece following a family tragedy. She prioritizes her career opportunities in Frankfurt over raising a child, leading her to deposit the girl with a reclusive relative. She is pragmatic and concerned with appearances and social mobility.

A wealthy businessman who frequently travels for work. He is a kind, fair-minded father who prioritizes his daughter's happiness over strict social decorum, often overruling his housekeeper's severe judgments.

An insightful, warm elderly woman who brings life into the Sesemann household during her visits. She understands children far better than the strict household staff and uses patience and storytelling to encourage learning.

A young servant in the Sesemann household in Frankfurt. He is sympathetic to the confusion of city life, occasionally helping hide treasures or subvert the housekeeper's rigid rules for a bit of humor.

A dedicated physician and a trusted friend of the Sesemann family. Grieving the recent loss of his own daughter, he is a compassionate medical professional who accurately diagnoses the emotional roots of physical ailments.

A hardworking woman who struggles to maintain a poor household on the mountain. She worries constantly about providing for her family and ensuring her son receives an education.

A woman from the village who serves as a voice for the town's collective opinions. She expresses deep concern about leaving a young child with a man who has a frightening reputation.

An educator hired by the Sesemann family in Frankfurt. He is a patient teacher who welcomes the challenge of instructing an illiterate student, even when the house manager insists the child is unteachable.

A maid in the Sesemann household who follows strict orders and shows little patience for rural habits or messes.

A deceased woman who died of grief shortly after her husband's tragic accident, leaving her young daughter an orphan.

A carpenter's apprentice whose sudden death fractured his family and prompted his father's complete withdrawal from society.

One of two goats kept at the mountain hut. She provides nutritious milk that becomes a staple of the household diet.

The second goat belonging to the small mountain household, contributing to the daily milk supply and serving as an animal companion.

An orphaned young goat in the village flock who quickly becomes a favorite during trips to the high mountain meadow.

The church leader from Dörfli and a former neighbor of the mountain's most reclusive resident. He represents the village's institutional authority and attempts to pressure his former neighbor into returning to civilized society.

A young boy working on the streets of Frankfurt with his pet tortoise. He acts as a paid guide through the city streets.

A local tradesman who provides transportation and shares village gossip regarding the mountain's residents.