Annabelle is an eight-year-old china doll who has lived in the Palmer family's dollhouse for over a century. She is brave, curious, and restless, chafing against the strict rules of the Doll Code that govern her family's existence. Inspired by her missing aunt, she decides to investigate the decades-old mystery of her disappearance.

Tiffany is a modern, plastic doll who becomes Annabelle's best friend. She is boisterous, confident, and fearless, happily participating in chaotic games and shrugging off the strict conventions of older toys. Her adventurous spirit makes her a willing partner in Annabelle's secret society, SELMP.

Auntie Sarah is Annabelle's adventurous relative who mysteriously disappeared 45 years ago. According to her hidden journal, she possessed a deep fascination with learning, nature, and exploration. She serves as a powerful role model for Annabelle, inspiring the young doll's courage and curiosity.

Uncle Doll is Sarah's husband and the uncle of Annabelle and Bobby. Though initially timid and fearful like the other adults, he harbors lingering regrets about his wife's disappearance. He proves willing to support Annabelle's quest, leading to friction with the more conservative adults in the dollhouse.

The Captain is the Palmers' household cat. Acting on feline instinct rather than malice, he stalks the halls and views the living dolls as chew toys, making him a constant source of terror for the cautious Doll family.

Mama Doll is Annabelle's china doll mother. She is highly conventional, deeply fearful of the Doll Code's penalties, and prefers the safety of established routines. She discourages her children from taking risks and views the modern Funcraft family with initial apprehension.

Papa Doll is Annabelle's father, a traditional china doll who values safety and propriety. Like his wife, he strictly adheres to the Doll Code and worries about the dangers of the Palmer house, though he proves capable of surprising bravery when his family faces immediate danger.

Nanny Doll is the caretaker for the Doll family children. She is an older, strict adherent to the Doll Code who constantly warns Annabelle about the terrible consequences of being discovered by humans, fearing they will be treated like circus attractions.

Bobby Doll is Annabelle's younger brother. He is a playful china doll who looks up to his older sister and occasionally joins her on early excursions outside their home, though he maintains a healthy fear of the outside world.

Kate Palmer is the nine-year-old human owner of the Doll family. She represents the fourth generation of her family to own the antique dollhouse. She is a careful, conventional child who treats the dolls gently and meticulously arranges their home.

Nora is Kate's younger sister, a rambunctious preschooler who receives the Funcraft dollhouse for her birthday. Her playstyle is rough, messy, and anarchic, making her the perfect owner for the durable Funcraft dolls but a terror to the fragile china Doll family.

Mom Funcraft is Tiffany's mother, a plastic doll who cheerfully embraces her family's loud, unconventional lifestyle. She astonishes the older toys by exuberantly sliding down their banister during a neighborly visit.

Dad Funcraft is Tiffany's father, an energetic plastic doll who is immensely proud of his family's rowdy antics. He views the household cat as an amusing plaything rather than a deadly threat, eagerly engaging in games of chase.

Bailey is Tiffany's younger brother. He happily participates in Nora Palmer's chaotic games, finding it amusing when he is tossed into a toy sink, and eventually forms a bond with the cautious Bobby Doll.

Grandma Katherine is Kate and Nora's grandmother, who owned the Doll family when she was a little girl. She retains a lingering curiosity about whether the antique toys might actually be alive and occasionally intervenes when the dolls are damaged.

Annie Palmer is Kate and Nora's mother, who manages the busy household. She accidentally triggers Annabelle's terrifying Doll State when the little doll runs directly into her foot in the dark.

Baby Betsy is the infant sister in the china Doll family. Kept safely inside the dollhouse, she eventually gains a modern playmate when the new plastic dolls move in next door.

Baby Britney is the plastic baby doll in the Funcraft family. Thanks to her durable construction, she easily survives being subjected to wild flights through the air during Nora's play sessions.

Rachel is Kate Palmer's human best friend. Though she is never seen interacting with the dolls directly, her enthusiastic conversations about Nancy Drew mysteries inspire Annabelle to begin her own investigation.