Elphaba is a young woman born with green skin who grows up isolated and misunderstood in Oz. Highly intelligent and passionate about political causes, particularly Animal Rights, she struggles to find her place in a society that judges her on her appearance. She pushes against the expectations of her family and the rigid norms of Shiz University.

Glinda is a beautiful, wealthy, and socially graceful student at Shiz University. Originally going by the name Galinda, she is highly concerned with appearances, social standing, and fitting in with her peers. Over time, her worldview expands as she is exposed to new ideas and different types of people.

Fiyero is a Winkie prince from the Vinkus region, distinguished by his blue-diamond skin. He is introduced as a student at Shiz who is already married due to his culture's traditions. Wealthy and somewhat aloof, he observes the social and political tensions in Oz with a growing awareness.

The Wizard is the despotic ruler of Oz who wrested power from the Ozma Regent years prior. He employs a totalitarian approach to governing, implementing laws that increasingly restrict the rights of Animals and marginalized communities. He relies on mystery, fear, and a vast network of spies to maintain his hold over the land.

Madame Morrible is the imposing and conservative headmistress of Crage Hall at Shiz University. She enforces strict decorum among her female students and propagates the Wizard's political agenda. She actively seeks to mold promising young women into agents for the government, using intimidation to assert her authority.

Yackle is a mysterious and enigmatic figure who appears in various guises throughout Elphaba's life. Whether acting as a sorceress, a performer in a seedy club, or a nun in a convent, she possesses an eerie foresight regarding Elphaba's destiny. Her constant, inexplicable presence suggests she plays a significant role in guiding events from the shadows.

Dorothy Gale is a young, innocent girl from another world who unwittingly becomes a central figure in Oz's political and magical conflicts. Sweet, demure, and desperate to return home, she quickly charms the Ozians she meets. Her sudden arrival and possession of powerful artifacts place her on a collision course with the land's established powers.

Frex is a devoted minister who preaches the values of the Unnamed God. He is deeply committed to his faith and his parish, often prioritizing his missionary work over his family. His religious zeal and rigid moral code make it difficult for him to connect with his wife and his unconventional eldest daughter.

Melena is Elphaba's mother, a woman born into the upper echelons of society who struggles with the narrow boundaries of her life in Munchkinland. Bored by her marriage to a pious minister and dissatisfied with her social standing, she frequently seeks comfort in earthly pleasures, alcohol, and the company of strangers.

Nessarose is Elphaba's younger sister, born without arms but possessing a striking beauty. Raised with preferential treatment from their father, she is deeply religious and poised to inherit the title of Eminent Thropp. Her pious nature and sheltered upbringing contrast greatly with her older sister's rebellious and independent spirit.

Boq is a short, affable young man from Munchkinland who attends school in Shiz. He is kind-hearted and well-meaning, harboring an enduring crush on Glinda while maintaining a steady, loyal friendship with Elphaba. He quietly supports Elphaba's interest in Animal Rights despite the political risks.

Doctor Dillamond is an Animal professor at Shiz University who possesses the mind of a human in the body of a Goat. He is a dedicated scientist researching the biological distinctions between animals and Animals. His progressive teachings and outspoken nature make him a target in an increasingly prejudiced society.

Nanny is the pragmatic and loyal caretaker for the Thropp family. Originally Melena's nanny, she returns to help raise Elphaba and Nessarose, eventually acting as a chaperone at Shiz. She is deeply invested in the family's well-being, providing a grounding presence during their various eccentricities and tragedies.

Turtle Heart is a large, affable Quadling glassblower who wanders into Melena and Frex's lives. Despite hailing from a marginalized class, his playful demeanor and genuine warmth endear him to the isolated family. He brings a brief period of joy and affection to the household before tragedy strikes.

Liir is a quiet young boy who travels with Elphaba after she leaves the convent. He struggles to fit in with other children and longs for a traditional family structure. His exact parentage and background are subjects of rumor and mystery.

Sarima is Fiyero's widow, a woman from the Vinkus who adheres strictly to the customs of hospitality. She allows Elphaba to live in her home but steadfastly refuses to discuss the details of her late husband's life in the Emerald City, preferring the comfort of ignorance over painful truths.

Shell is Elphaba and Nessarose's younger brother, born without physical deformities. He represents the ideal child his parents always wanted but grows up in an increasingly unstable and dangerous political climate.

Chistery is a snow monkey adopted and raised by Elphaba. She attempts to teach him language in hopes of proving the intelligence of animals, making him a loyal companion and a key part of her isolated life.

Nor is Sarima's young daughter, who becomes enamored with the visiting military forces. Her innocent desire for attention and connection has profound consequences for her entire family as the political climate darkens.

Ama Clutch is Glinda's chaperone at Shiz University. She is responsible for overseeing the young women's moral and social conduct. Her presence is a marker of Glinda's high social standing, and her eventual tragic decline deeply affects her charges.

Grommetik is a tiktok, a mechanical contraption that serves as a spy and enforcer for Madame Morrible. It operates without human emotion, strictly following the orders of its master in the increasingly oppressive political atmosphere of Shiz University.