- Played By: Adam Sandler
Nicky is the third son of Satan and Satan's favorite son compared to Adrian and Cassius. Nicky is into rock music and Popeye's chicken.
- Anti Anti Christ?: Nicky is quite a likable son of the devil.
- Black Speech: Nicky's sleep talk.
- Born of Heaven and Hell: The son of Satan and an angel, which is why he's a nice guy who does enjoy darker things. He is well liked by both the denizens of Hell, with the exception of his half-demon brothers, and Heaven. He also has the ability to travel to Heaven or Hell after "death" on Earth, which requires him to do something good (Heaven) or bad (Hell) beforehand.
- Catchphrase: Get in the flask!
- Death Is Cheap: Nicky was born in Hell and left it near the start of the movie. Dying and being sent back there just means he gets to leave and try again.
- Dumb Is Good: Nicky is far dumber than Adrian. One character even flat out remarks that there's no way Nicky can outsmart him.
- It's implied that Nicky isn't dumber because he's good, so much as because he's suffered a lot of head trauma over the years. Thanks to his brothers.
- Meaningful Name: "Old Nick" is an old folkloric nickname for the devil.
- Parental Favoritism: Nicky, apparently. Which might explain why his brothers pick on him so much.
- Precision F-Strike: After Nicky ate Popeye's chicken for the first time.Nicky: Popeye's chicken is fucking awesome!
- Rock Me, Asmodeus!: Ironically, Satan's least evil son is a fan of heavy metal and hard rock.
- Speech Impediment: Nicky gained this after Cassius hit his throat with a shovel.
- They Killed Kenny Again: Nicky is killed seven times. Being a denizen of Hell, he can just walk right back out. Deaths include: Being hit by a train twice, being hit by a truck and a bus, attacked by a polar bear off-screen, drowned by his roommate and for the finale hit in the head with a large rock.
- Played By: Rhys Ifans
Adrian is the first-born son of Satan. He is very vicious and flamboyant.
- Bat Out of Hell: He can transform into one.
- Big Bad: After Cassius was taken in.
- Big Bad Duumvirate: With Cassius before Cassius was taken.
- Evil Brit: Adrian is portrayed with the accent of an Upper-class British villain. His actor, Rhys Ifans, is also British (Welsh).
- Large Ham: He likes to ham things up in his dialogue.
- Off with His Head!: He is defeated by having his head bit off by Ozzy Osbourne while in bat form.
- Son of a Whore: Adrian's mother is a prostitute.
- Played By: Tommy Lister Jr.
Cassius is the second-born son of Satan. He is the most aggressive of the three sons.
- Voiced By: Robert Smigel
Mr. Beefy is a talking bulldog and an old friend of Satan. He guides Nicky through New York.
- Played By: Allen Covert
Todd is Nicky's roommate at New York. He is also an actor.
- Played By: Harvey Keitel
Satan is the second ruler of Hell and decided not to have any of his sons to succeed him for the next ten thousand years. Now that Cassius and Adrian left Hell with his Fireball of Hades, Satan is falling apart.
- All There in the Manual: A Deleted Scene reveals that he made the flask so that the Fireball of Hades that is keeping him alive will be regained.
- And I Must Scream: When he is falling apart from his body to just his mouth.
- Deal with the Devil: Subverted. Dan Marino wants to sell his soul to Satan, but he's rejected because Satan thinks he's too much of a nice guy to go to Hell...and because he's a Jets fan.
- Dirty Old Man: Somewhat as the ruler of Hell like his father before him.
- Everyone Calls Him "Barkeep": "Satan" is implied to be a title, since his successor will be "the new Satan". His actual name is not revealed.
- Satan Is Good: He punishes sinners, maintains the balance of good and evil, and is a supportive dad who only wants what's best for Nicky. He's fine with him living on Earth.
- You Have Failed Me: He punished Stanley by giving him two giant breasts on his head after Stanley failed to stop Adrian and Cassius from leaving.
Jimmy the Demon
- Played By: Blake Clark
Jimmy is the Secretary of State of Hell and often reminds Satan of his usual punishments.
- Played By: Rodney Dangerfield
Lucifer is the founder of Hell, the father of the current Satan, and Nicky's grandpa.
- Dirty Old Man: He asks if he can have Stanley for awhile to play with his tithead. Later, he gets turned on when Adrian gives Stanley a burble nurple.
- Legacy Character: Lucifer is the original Satan who founded Hell twenty thousand years before the events of the film, after getting kicked out of Heaven.
- Our Founder: Lucifer is the founder of Hell. In a Deleted Scene, Hell's original name was Boogerland.
- No Respect Guy: Even in Hell, Lucifer gets no respect.
- STD Immunity: Implied in a Deleted Scene that he doesn't use condoms. His son insists.
- Played By: Kevin Nealon
Stanley is the gatekeeper of Hell with breasts on his head.
- Voiced By: Jess Harnell
Gary is a primate who lives in Hell is and good with the people around him.
- Played By: Jonathan Loughran (John), Peter Dante (Pete)
John and Peter (Pete) are two heavy metal fans who like to help Nicky.
- Died Happily Ever After: After they died from a plane crash, they went to Nicky's room in Hell.
- Heterosexual Life-Partners: Both of them look after each other.
- Meaningful Name: They have the names of Jesus's most prominent disciples - common names for sure, but because of that.
- Metalhead: They serve as the trope illustrator, and further lean into the stereotype/accusation about rock and metal being Satanic by being some kind of devil-worshippers themselves.
- Only Known By His Nickname: Pete is listed as "Peter" in the credits but in the dialogue it's always "Pete".
- The Stoner: They get themselves, Nicky and Todd high after spiking a cake with reefer.
- Those Two Guys: They are never seen apart.
- True Companions: They swear to be Nicky's slaves forever.
- Played By: Reese Witherspoon
Holly is an angel of Heaven and the mother of Nicky.
- Everything's Precious with Puppies: Her cell phone makes puppy noises.
- Luke, I Am Your Father: Or mother, in this case.
- Really 700 Years Old: Angels don't age, which is the reason she looks younger than her own son.
- Valley Girl: What she and her friends sound like.
- Walking Spoiler: Talking about the character spoils the twist.