Beings killed by Castiel.
Angels
Archangels
- Raphael - Exploded at the molecular level while empowered by the souls of Purgatory.
Intelligence Angels
- Ion - Pushed an angel-killing bullet through his right eye to escape Ion and Crowley.
Reapers
- Billie - Stabbed through the back with an angel blade to break her deal with the Winchesters.
Regular Angels
- One of Raphael's Incursion Angels - Stabbed with an angel blade during the Skirmish at Balthazar's Mansion.
- Pharmacist Angel - Stabbed with an angel blade in self-defense.
- Balthazar - Stabbed through the back with an angel blade after discovering Balthazar had betrayed him to the Winchesters.
- Bartholomew - Stabbed in the abdomen with an angel blade in self-defense.
- Daniel - Stabbed through the back with an angel blade to save Hannah.
- Efram - Stabbed in the chest with an angel blade.
- Adam's Angel Escorts - Stabbed with an angel blade at Adam Milligan's resurrection site.
- Three of Malachi's Faction - Stabbed with an angel blade after stealing Theo's grace.
- Metatron's Assassins - Killed with an angel blade in self-defense during Operation: Lee Harvey.
- Hael - Stabbed in the chest with an angel blade after being pressured to become her vessel.
- Ishim - Stabbed through the back with an angel blade to save Lily Sunder.
- Raphael's Loyalists - Smote in Heaven after declaring himself "the new God."
- Jonah - Stabbed in the abdomen with an angel blade.
- Rachel - Stabbed with an angel blade in self-defense.
- Samandriel - Stabbed in the stomach with an angel blade while under the control of Naomi.
- Theo - Throat slit and grace absorbed then smote.
- Zachariah's Foot-Soldiers - Stabbed through the neck and in the back respectively with an angel blade in order to save Sam and Dean Winchester.
- One of Zachariah's Guards - Stabbed with an angel blade outside the Green Room.
Rit Zien
- Ephraim - Stabbed in the chest with an angel blade.
Nephilim
- Jane - Stabbed through the neck with an angel blade and cut out her heart for Metatron's spell.
Demons
Princes of Hell
- Dagon - Incinerated while empowered by Jack.
Regular Demons
- Crowley's Assassins - Smote to protect the Winchesters and Bobby Singer from an attack.
- Castiel's Captive - Tortured for information on the location of Cain then stabbed through the chest with an angel blade.
- Two of Claire's captors - After taking Claire Novak as his vessel briefly, Castiel smote two of her captors.
- Meg's Captors - Smote at the Murray Hotel while rescuing Meg.
- Ellsworth - Forced back into his vessel and then smote so that he could not tell the Winchesters that Crowley is alive.
- Ellsworth's Hunters - Two demons capturing monsters for Elsworth who were smote by Castiel to keep the Winchesters from finding out the truth about Crowley's survival.
- Three Tablet Hunters - Smote two, stabbed a third with an angel blade.
- One Iowa Factory Guard - Smote while rescuing Kevin Tran and the future Prophets.
- Monster Prison Guards - Killed when Castiel destroyed Crowley's Monster Prison and all inside it.
- One of Dean's Captives - Smote to save Dean's life.
- Pestilence's assistant - Stabbed in the abdomen with the demon-killing knife after defeating Pestilence.
- Marcus - Smote by Castiel at the Northern Indiana State Hospital to save Sam Winchester.
- Demon Medics - Smote by a memory-less Castiel outside the Northern Indiana State Hospital.
- Hundreds of demons - As an angel, Castiel has killed hundreds of demons over the millennia.
Monsters
Jefferson Starships
- Around a dozen Jefferson Starships - Blasted with holy white light.
- Cop Jefferson Starship - Decapitated by Castiel with a machete before it could attack Bobby Singer.
- Prisoner Jefferson Starship - Brutally tortured by Castiel for Eve's location and then decapitated.
Leviathans
- Dick Roman - Briefly restrained so Dean could stab Dick through the neck with the Bone of Righteous Mortal Washed in the Three Bloods of Fallen.
Vampires
- Lenore - Smote at her request.
- Unnamed Purgatory Vampire - Smote while fighting alongside Dean and Benny Lafitte.
Zombies
- An unnamed Croatoan zombie - Decapitated with a shotgun blast to save Sam's life during the Raid on Niveus Pharmaceuticals.
Other Monsters
- Crowley's Monster Prison - Killed all of the monsters within the prison at the Winchesters' request.
- Brigitta - A djinn held prisoner by Crowley when Castiel slaughtered the prison's inhabitants.
- Unnamed Rugaru - One of the prisoners.
Humans
Hunters
- Hundreds of Dean Winchester clones - Killed in various ways by Castiel as part of his training under Naomi.
Vessels
- Alfie - Killed along with Samandriel by Castiel.
- Gloria Lewellen Jacobson - Killed along with Hael by Castiel.
- Ann Morton - Killed along with the demon possessing her by Castiel.
- Wendy Rice - Killed along with the demon possessing her by Castiel.
- Balthazar's vessel - Killed along with Balthazar by Castiel.
- Bartholomew's vessel - Killed along with Bartholomew by Castiel.
- Ephraim's vessel - Killed along with Ephraim by Castiel.
- Ion's vessel - Killed along with Ion by Castiel.
- Ishim's vessel - Killed along with Ishim by Castiel.
- Raphael's second vessel - Killed along with Raphael by Castiel.
- Numerous other vessels - Killed along with the angels possessing them by Castiel.
Other
Four Horsemen of the Apocalypse
- Pestilence - Cut off his ring with the demon-killing knife, leaving him permanently incapacitated.