Characters in The Lightning Thief

Percy Jackson

Twelve-year-old son of Poseidon discovering his demigod identity.

Also in The Sea of Monsters, The Titan's Curse, The Battle of the Labyrinth, Percy Jackson and the Sword of Hades, The Last Olympian, Percy Jackson and the Singer of Apollo, The Chalice of the Gods, The Son of Neptune, Wrath of the Triple Goddess, The Mark of Athena

Annabeth Chase

Daughter of Athena and Percy's quest companion.

Also in The Sea of Monsters, The Titan's Curse, The Battle of the Labyrinth, The Last Olympian, The Chalice of the Gods, The Lost Hero, Wrath of the Triple Goddess, The Mark of Athena, House of Hades, The Blood of Olympus

Grover Underwood

Satyr protector assigned to guide Percy.

Also in The Sea of Monsters, The Titan's Curse, The Battle of the Labyrinth, The Last Olympian, Percy Jackson and the Singer of Apollo, The Chalice of the Gods, Wrath of the Triple Goddess, The Blood of Olympus, The Burning Maze, The Titan's Curse: The Graphic Novel

Chiron

Immortal centaur who trains heroes; poses as Percy's Latin teacher before revealing himself.

Also in The Sea of Monsters, The Titan's Curse, Wrath of the Triple Goddess, The Hidden Oracle, Camp Half-Blood Confidential

Poseidon

God of the sea and Percy's absent divine father.

Also in The Titan's Curse, The Chalice of the Gods

Hades

God of the Underworld, initially suspected of orchestrating the theft.

Also in Percy Jackson and the Sword of Hades, The Last Olympian, The Mark of Athena, House of Hades, The Blood of Olympus

Zeus

Also in The Titan's Curse, The Chalice of the Gods, Percy Jackson's Greek Gods

Dionysus

Also in The Titan's Curse

Ares (god)

Also in The Sea of Monsters, The Titan's Curse