Artemis is a 12-year-old child prodigy and the heir to a family of criminals. Following the disappearance of his father and the subsequent deterioration of his mother's health, he assumes control of the Fowl estate. He uses his vast intellect and technological resources to orchestrate a plan to restore his family's lost fortune by extorting the hidden world of fairies.

Holly is an elf and an officer in the Lower Elements Police (LEP) reconnaissance squad. As the first female officer in her unit, she operates under intense scrutiny and feels heavy pressure to perform flawlessly. She dedicates herself to protecting the subterranean fairy society from human discovery, though she struggles to maintain the magical energy required for her job.

Butler is a massive, highly trained bodyguard from a family lineage dedicated to protecting the Fowls. He serves as Artemis's primary enforcer and the closest figure the boy has to a father. He executes Artemis's dangerous plans with strict efficiency, though he maintains a personal code of honor.

Root is the red-faced, short-tempered leader of the LEP reconnaissance squad. He represents the traditional, magic-reliant old guard of fairy law enforcement. He aggressively manages the crisis at Fowl Manor, prioritizing the safety of his officers over the experimental tactics suggested by his rivals.

Foaly is a paranoid centaur who serves as the technical wizard for the Lower Elements Police. He designs and monitors all the advanced technology used by the fairies, frequently wearing a tinfoil hat to block imagined human surveillance. He takes great pride in outsmarting opponents with science rather than magic.

Mulch is a kleptomaniac dwarf who gave up his magic in order to freely break the fairy rules regarding human dwellings. He possesses the biological ability to tunnel rapidly through the earth by consuming and expelling soil. Because of his criminal background and lack of magic restrictions, the LEP recruits him for an unorthodox infiltration.

Angeline is Artemis's mother, who suffers from severe anxiety and delusions following the disappearance of her husband. She remains confined to her room, leaving Artemis unsupervised to run the estate. Her poor health acts as the emotional catalyst for her son's extreme actions.

Juliet is Butler's younger sister and serves as a maid and caretaker for Angeline Fowl. She assists with the preparations for Artemis's plans without fully understanding the magical dangers involved. She maintains a tough exterior but remains an innocent bystander in the conflict between the fairies and the Fowls.

Artemis Senior is the former head of the Fowl criminal empire. He disappeared a year prior to the story after attempting to establish new shipping channels to Russia. His absence leaves a massive void in the Fowl family, driving his son to take extreme measures to restore their wealth.

Cudgeon is an ambitious officer in the Lower Elements Police. Unlike Root, he cares more about personal glory and career advancement than the safety of his fellow fairies. He prefers aggressive, uncontrolled tactics to resolve the hostage situation.

Dr. J. Argon is a psychiatrist working for the Lower Elements Police. He compiles and presents the case file on Artemis Fowl, documenting the boy's psychological profile and his first major conflict with the fairy world.

Nguyen is a human informant who provides Artemis with a crucial lead on a fairy living in Vietnam. He helps the boy locate a magical healer in exchange for payment, facilitating Artemis's acquisition of the fairy rulebook.

Captain Trouble Kelp is a field officer for the Lower Elements Police. He participates in the assault on Fowl Manor and directly encounters the physical might of Artemis's bodyguard.