This a list of those who died in the series, and those who are mentioned to have died before the series. However, keep in mind that monsters on this page may, will, or have already reformed from Tartarus. Characters in bold are considered protagonists that readers may/may not mourn. Characters in italics are considered antagonists(ex. monsters). Characters in underline are mostly unimportant/in the middle.
Before the series
- Maria di Angelo - Died in a hotel explosion caused by Zeus, which was intended to kill Nico and Bianca di Angelo's.
- Laura Jackson - Died in a plane crash.
- [[Jim Jackson|
File:Images Hazel.jpg Jim Jackson]] - Died in a plane crash.Hazel Levesque, who died in the 1940s but was brought back from the Underworld by her half brother Nico di Angelo.
- Rich Jackson - Died from cancer.
- The Oracle's host - Died over thirty years before The Lightning Thief and became mummified after Hades cursed her.
- Grover's Uncle Ferdinand - Died after being turned to stone by Medusa.
- Beryl Grace - Died in a car crash caused by her being drunk.
- Esperanza Valdez - Killed in a fire in her workshop which was caused by Gaea, who later made Leo believe that he himself had caused the fire.
- Marie Levesque - Killed when Alcyoneus almost rose.
- Hazel Levesque - Killed when Alcyoneus almost rose by forcing the cavern she was in to collapse on her, suffocating to death from being trapped in oil. She was brought back to life by Nico di Angelo.
- Michael Varus and his group from Camp Jupiter are defeated in Alaska.
- Sammy Valdez - Died of old age.
- Various demigod children of Athena who were searching for the Athena Parthenos. Some were killed by:
- Cottus - faded away.
- Gyges - faded away.
- Various Satyrs while looking for Pan.
- Mr. McCaffrey - Killed by Nero so he could take his daughter as his own.
Percy Jackson and the Olympians
The Lightning Thief
- The Minotaur - Percy killed it with one of its horns.
- Reformed some time before The Last Olympian, but killed again by Percy during the Battle of Manhattan.
- Hellhound- shot in the side by Chiron.
- The Furies - Alecto was killed at Metropolitan Museum by Percy Jackson, but reformed later.
- All three Furies were killed on a bus by Percy Jackson, Annabeth Chase, and Grover Underwood, but later reformed again.
- Medusa - Head sliced off by Percy.
- Procrustes - Head sliced off by Percy.
- Unnamed preacher - fell off a cliff during a police chase because he was scamming people. Percy and Grover recognized him in the Underworld.
- A Boar - drowned by Percy in the fight against Ares.
- Gabe Ugliano - Killed when Sally Jackson turned him to stone with Medusa's head. Sally sells him as a statue named The Poker Player.
- Pit Scorpion - chopped in half by Percy.
The Sea of Monsters
- Laistrygonian Giants- killed by Annabeth, Tyson, and Percy.
- Joe Bob - stabbed by Annabeth.
- Skull Eater - Killed when Tyson punched him in the face.
- Marrow Sucker - Killed when Tyson Deflected a Flaming Dodgeball.
- Stymphalian Birds - Killed by Apollo Demigods at Camp Half-Blood.
- The Hydra - Killed by the CSS Birmingham's cannons.
- Confederate Sailors - When the CSS Birmingham exploded (though technically already dead).
- Circe - (Presumably, as she is a goddess) Killed by Edward "Blackbeard" Teach when he was freed from his curse of being a Guinea Pig.
- Deer - Eaten by flesh-eating sheep.
- Unspecified Drakon - Killed after starting a fire at Camp Half-Blood
- Oreius - shot in the mouth by a centaur with a bow and arrow.
- Agrius - Kicked in the head by Blackjack.
- Probably other monsters killed by campers while the Questers are away.
The Titan's Curse
- Nemean Lion - Killed by space food, and Zoe's arrows at the Smithsonian
- Dr. Thorn the Manticore - Killed by Dionysus
- Talos (prototype) - destroyed by Bianca di Angelo.
- Bianca di Angelo - Died when the malfunctioning Talos prototype, a creation of Hephaestus, toppled over onto an electric cable with her inside. Her body was never found.
- Skeleton Warrior(s) - banished to the Underworld by Bianca. Another group were sent to the Underworld by Nico di Angelo
- Zoë Nightshade - Killed by Ladon's poison and Atlas' (her father) final blow.
- There were many monsters killed when Dr. Chase rescued everyone.
The Battle of the Labyrinth
- Tammi - Killed by Percy in Goode High School
- A boy from Seattle - He was mentioned by Kelli to Luke that he was just a snack.
- Antaeus - stabbed by Percy in his third and final duel.
- Dracaenae - Killed in Percy's first duel (out of three).
- Centaur - Killed by a Laistrygonian Giant in a duel.
- Geryon- Killed by Percy shooting an arrow hitting all three of his hearts.
- Pan - Faded away because of the nature and wild dying.
- Many animals (including Dede the Dodobird, a sabertooth tiger, and a woolly mammoth) were turned to dust when Pan faded.
- An Unnamed Satyr - trampled on and presumably killed by a Hellhound (see below) Percy started to help him when Juniper's tree started burning.
- A Hellhound - After killing a Satyr, it targeted Percy and was stabbed with Riptide.
- Kelli- Killed by Annabeth in the Labyrinth.
- Kampê - Killed by Briares near Zeus's Fist.
- Lee Fletcher, son of Apollo - Squashed by a giant.
- Castor, son of Dionysus - Brought down by an enemy demigod during the Battle of the Labyrinth.
- Daedalus - Nico released his spirit.
- There were many unrecorded deaths in the Battle of the Labyrinth including those of many Camp Half-Blood campers, enemy demigods, and monsters.
The Demigod Files
- Keres - Killed by Percy, Thalia, and Nico during an ambush.
- Stymphalian Birds - Killed by Percy and Clarisse
- Myrmekes - Electrocuted and burned by the Bronze dragon, in order to rescue Beckendorf.
- The Bronze Dragon - shut down by Beckendorf after it went rogue. Later rebuilt.
The Last Olympian
- Charles Beckendorf - Died in the explosion of the Princess Andromeda.
- A Giant Crab - Stabbed in a soft spot on his stomach by Percy.
- Numerous Telkhines and Dracaena were killed by Percy prior to the explosion of the Princess Andromeda
- Hundreds of Kronos's warriors- Destroyed in the explosion of the Princess Andromeda.
- A Giant Squid - Turned into a lot of Goldfish by Poseidon.
- The Minotaur - Reformed since The Lightning Thief, though is soon killed by Percy again with his own axe.
- A member of Apollo's Cabin, dragged off by a Hellhound.
- Michael Yew - Died when Percy stabbed Riptide into Williamsburg Bridge, collapsing it. His body is never found, though he is confirmed as deceased in The House of Hades.
Luke died while stopping Kronos from evolving to his true form
- Leneus - Killed in The Battle of Manhattan, reincarnates into a Laurel tree.
- Hyperion - Turned into a maple tree by Grover and the satyrs.
- The Clazmonian Sow - Killed by Percy, with the assistance of a few automatons.
- Silena Beauregard - Died fighting a drakon.
- Lydian Drakon - Killed by Clarisse after Silena's death.
- An unnamed Child of Ares - Eaten by the Lydian Drakon.
- Queen Sess - Shot by Chiron with a bow and arrow.
- Ethan Nakamura - died when a shard of his own sword hit him in the stomach after he slashed at Kronos. He was later sucked into a fissure on Olympus, and fell to his death.
- Kronos - Dissolved to dust when Luke Castellan stabbed himself with Annabeth's dagger. He is not dead, but has spread so thin that he'll probably never be able to form a consciousness again (as said by Hermes). a fate that his mother, Gaea, ultimately repeats.
- Luke Castellan - Killed himself to stop Kronos from evolving into his true form.
- A Hunter- Said to be knocked out of a tree by enemy arrows.
- The Oracle, who was already dead, was now dissolved so that Rachel Elizabeth Dare could take the spirit of the Oracle.
- There were many unrecorded deaths in The Battle of Manhattan as there was simply too many to count and too little time. According to the The Demigod Diaries, 1000 demigods that fought for Kronos were killed, while 16 Camp Half-Blood demigods were killed total.
- Many Nature Spirits were killed by Titan Army Scouts.
- Typhon- Chained, stabbed by Poseidon, and sent down a "slip-n-slide" into Tartarus.
- 20 Satyrs at Fort Washington.
Percy Jackson's Greek Gods
- Titans Iapetus, Koios, Krios (reformed during The Last Olympian, killed by Jason Grace), Hyperion (reformed during The Last Olympian, killed by Percy and the satyrs.)
- Erisikthon
- Askalaphos, Hades' personal gardener (though already dead)
- Most mortals by Zeus
The Heroes of Olympus
The Lost Hero
- Venti - Dissolved when Jason stabbed them.
- Sump - Killed by Leo's machine (reformed almost instantly).
- Torque - Killed by Leo's machine (reformed almost instantly).
- Ma Gasket - Smashed by an engine block (reformed almost instantly).
- Festus - Shot down by lasers
- Medea - Died in an explosion
- Two sun dragons - Destroyed in an explosion
- King Midas - Presumably killed by a crowd of his victims
- Lityerses - Turned to gold (possibly turned back)
- Earthborn- Killed by Jason, Piper, and Leo. Several were also killed by the Hunters later.
- Lycanthropes - Killed by the Hunters of Artemis
- Enceladus - Killed by Jason with a lighting bolt from Zeus
- Various other monsters - destroyed when Hera unleashed her true form.
The Son of Neptune
- Stheno - Drowned by Percy in the Tiber (later reforms)
- Euryale - Drowned by Percy in the Tiber (later reforms)
- Gwen - Presumably killed by Octavian (comes back due to the open Doors of Death)
- Three Basilisks - Killed by Frank's skeletal warrior Gray
- Phineas - Poisoned with Gorgon blood by Percy during a bet.
- Otrera- killed by Hylla twice
- Six Laistrygonians - Killed by Frank with Gray
- Laistrygonian Giants - Killed during the escape from the Zhang mansion.
- Gryphons - Killed by Percy, Frank and Hazel (reformed).
- Shade Army - Killed by Percy when he destroyed the frozen camp.
- Alcyoneus - Killed by Frank and Hazel with the help of Arion.
- Enemy Cyclopes - Killed by the Fifth Cohort.
- Wild Centaurs - Killed by the Third and Fifth Cohorts.
- Karpoi Spirits - Killed by Percy with the Legion's Eagle.
- Basilisks - Killed by Percy with the Legion's Eagle.
- Multiple Earthborn - Killed by Percy with the Legion's Eagle. Some killed by Tyson with the help of Ella.
- Hundreds of other monsters - Killed by the Amazons and the 12th Legion.
- Polybotes - Killed by Percy with Terminus' head.
- Implied Roman campers- in battle at Camp Jupiter
- Multiple enemy Hellhounds killed by the Roman campers.
- Grandma Zhang (possibly) - died of old age after meeting Frank Zhang, Hazel Levesque and Percy Jackson.
The Demigod Diaries
- Halcyon Green - sacrificed himself in an explosion of Greek Fire to let Luke Castellan and Thalia Grace escape
- Leucrotae - two killed by Greek fire and one was engulfed by deadly curtain drapes
- Cacus - hit with metal claw by Annabeth then shot with Hermes' caduceus in laser mode by Percy
- Burly Black - set on fire by Lamia to horrify Dr. Howard Claymore
- Lamia - killed multiple times by Claymore and Alabaster
- Dr. Howard Claymore - sacrificed himself so that Alabaster could defeat Lamia (his soul now occupies a Mistform body)
The Mark of Athena
- Three Eidolons - the eidolons impersonate Archimedes' robots, but Leo manages to trap them inside the robots' wiring and make them short-circuit.
- Ephialtes and Otis - killed by Bacchus, with help from Percy and Jason.
- Arachne - injured by ballistae on the Argo II causing her to fall into Tartarus. Later killed in Tartarus by Percy Jackson.
The House of Hades
- Arachne - Killed by Percy with Riptide.
- Arai - Many were killed by the combined forces of Percy, Annabeth, and Bob.
- Kelli - Stomped on by Bob.
- Empousai - Destroyed by Bob.
- Maeonian drakon - killed everyday by Damasen.
- Katoblepones - killed by Frank
- Sciron - Eaten by his own pet giant turtle.
- Scipio - Euthanized by Reyna after being wounded by a gryphon.
- Many monsters killed at the Doors of Death by Tartarus.
- Pasiphae - fell into a tunnel created out of Mist by Hazel.
- Clytius - attacked by the Seven and the burned by Hecate.
- Bob - killed by Tartarus
The Blood of Olympus
- Bryce Lawrence - turned into a ghost by Nico.
- Mimas - killed by Phobos, Deimos and Piper.
- Octavian - shot into the air by an onager.
- Kinzie - killed by Orion.
- Phoebe - killed by Orion.
- Naomi - killed by Orion.
- Celyn - killed by Orion.
- Leo Valdez - temporarily killed by the explosion of Gaea. Resurrected with the Physician's Cure.
- Orion - killed by Reyna.
- Numerous Hunters - killed by Orion.
- Numerous Amazons - killed by Orion.
- Polybotes - killed by Jason and Kymopoleia.
- Enceladus - killed by Athena and Annabeth.
- Ephialtes and Otis - killed by Poseidon and Percy.
- Thoon - killed by the Fates.
- Periboia - killed by Piper and Aphrodite.
- Porphyrion - killed by Jason and Zeus.
- Gaia - Killed when Octavian's blast hits her, combined with Leo's fire, causing a massive explosion. (She is not dead, but has spread so thin that she'll probably never be able to form a consciousness again, a similar fate to that of her husband, Ouranos, and son, Kronos.)
The Trials of Apollo
The Hidden Oracle
- Millard - Died on his way to inform Rachel Elizabeth Dare about what is going on at camp.
- Several Myrmeke - One boiled in a geyser while fighting Apollo, others shot by arrows or died in cave in by the former God.
- Several Dryads - Sacrificed themselves to the extinguish a fire to save the Grove of Dodona.
Film
The Lightning Thief
- The Minotaur - attempted with Riptide, Percy killed it with one of its horns.
- Medusa - Head was cut off by Percy Jackson.
- Hydra - Turned to stone by Medusa's head.
- Hysterical Woman - Turned to stone by Medusa.
- Hysterical Woman's Husband - Turned to stone by Medusa before the woman (Not Shown).
- Gabe Ugliano - Turned to stone when opening the fridge with Medusa's Head in it.