A sixteen-year-old boy living in Florida who struggles to distinguish reality from the fantastical stories his grandfather told him. Feeling ordinary and misunderstood by his family, Jacob pursues a mystery following a traumatic event in the woods. His journey to the Welsh island of Cairnholm forces him to confront his past and realize his true capabilities.

Jacob's enigmatic grandfather, a refugee who escaped the Nazis and grew up in a Welsh children's home. He spent years telling Jacob wild tales of monsters and peculiar children, stories his family eventually dismissed as signs of mental decline. He is a fierce, secretive man whose past drives the central mystery.

Jacob's father, an aspiring ornithologist who struggles to finish his nature book. He has a complicated, distant relationship with his own father, Abraham, having felt abandoned by him during his childhood. Franklin's skepticism heavily contrasts with Jacob's growing belief in the peculiar world.

A psychiatrist tasked with helping Jacob process his grief and nightmarish visions following his grandfather's death. He encourages Jacob to travel to Wales to find closure, presenting himself as a supportive medical professional while taking an unusually deep interest in Jacob's family history.

The strict but caring headmistress of the peculiar children's home on Cairnholm. An ymbryne, she has the ability to manipulate time and transform into a bird, maintaining a temporal loop to keep her wards safe from outside dangers. She serves as a guardian of knowledge and a protector of the peculiar world.

A passionate and intensely loyal peculiar girl who can summon fire with her hands. She was deeply in love with Jacob's grandfather during his time at the home and struggles with feelings of abandonment over his departure. She acts as a bridge for Jacob into the hidden world of the peculiars.

An invisible peculiar boy living under Miss Peregrine's care. He is highly observant and scholarly, spending much of his time compiling an incredibly detailed book about a single day in the life of the Cairnholm villagers.

A peculiar girl with immense physical strength. She is deeply loyal to her friends and protective of her fellow peculiars, carrying a heavy emotional burden regarding her brother, Victor.

A somewhat morbid peculiar boy with the unsettling ability to take life from one object and temporarily grant it to another. He harbors a cynical streak and often points out the darker realities of living within the time loop.

Jacob's only friend in Florida, characterized by his green hair and tough demeanor. He helps Jacob investigate Abraham's ransacked house but eventually distances himself from Jacob following the traumatic events of that night.

An ymbryne and friend of Miss Peregrine who arrives at the loop in a state of terror. She brings dire news regarding attacks on other time loops, thrusting the children into high alert.

The curator of the small island museum on Cairnholm. He provides Jacob with historical context about the island and introduces him to his Uncle Oggie, helping Jacob piece together the timeline of the children's home.

Martin's elderly uncle and a longtime resident of Cairnholm. He remembers the bombing of the children's home on September 3, 1940, and provides Jacob with the crucial detail that one boy survived the blast.

The manager of the Priest Hole, the pub and inn where Jacob and his father stay on Cairnholm. He is a welcoming, conversational local who explains the history of the inn's name.

A local Cairnholm teenager and amateur rapper. He and his friend Worm initially trick Jacob by leading him to a ruined, excrement-filled house instead of the children's home.

Dylan's friend and fellow amateur rapper on the island. He participates in the prank played on Jacob when he first searches for his grandfather's old home.

A peculiar boy living in Miss Peregrine's loop who experiences prophetic dreams. He uses his abilities to foresee arriving dangers but struggles with the weight of his visions.

Jacob's aunt, who assists in clearing out Abraham's belongings after his death. On Jacob's sixteenth birthday, she gives him a critical gift: a copy of Emerson's works belonging to his grandfather.

Jacob's uncle, who co-owns the family's chain of Smart Aid stores. He suggests Jacob spend the summer in Tampa to prepare for inheriting the family business.

Bronwyn's deceased brother, a peculiar boy whose body is preserved within the time loop. His fate serves as a grim warning to the other children about the dangers that lurk outside their protected sanctuary.