Slick McPimperson (last name: 2005-01-21)(theres another strip where his last name is shady but im not going to go get refs for that)
- Human, White
- Male, Straight
- Beat Poet, Factory Worker
- Once stated to be "14-22"*

Sleaze - Slick's Dark Side
- Devil Person, Reflection
- Male, Straight
- Unemployed, Dark Side

Criminy
- Human, White
- Male, Presumably Ace
- Dating Fuchsia
- DJ, Breakdancer

Squigley "Squig" Fatwater  (last name: 2004-09-18)
- Pig, Male
- Straight
- Street Performer, Factory Worker

Monique "Nique""It-Girl" Hotpantz (last name: 2008-04-26)
- Human, Possibly Asian-American
- Female, Presumably Bi or Lesbian
- Dating Absinthe
- Beat Poet, Musical Artist
- Once stated to be "16"*

Demonique - Nique's Dark Side
- Devil Person, Shadow
- Female, Presumably Bi or Lesbian
- Dark Side, Tormentor of the Damned

Seymour XXXXXXX (last name unknown)
- Unknown, Nonhuman
- Male, Presumably Gay
- Preacher

The Devil, Satan, Lucifer, D-Man
- Fallen Angel, Devil Person
- Male, Straight
- Satan, Businessman
- Father to Li'l Evil

Li'l Evil, Li'l E, Lily
- Half Devil Person
- Male, Presumably Gay
- Son of The Devil and Liltih

Baby Blue
- Fallen Angel, Devil Person
- Female, Presumably Bi
- Fuchsia's Ex-Girlfriend
- Secretary, Torturer of the Damned

Absinthe "Abby"
- Devil Person
- Female
- Presumably Gay
- Dating Monique
- Booth Babe

Fuchsia "Fyoosh"
- Former Human, Devil Person
- Female, Presumably Bi
-Dating Criminy
- Artist, Unemployed

Sapphire "Saph"
- Devil Person, Female
- Presumably Gay
- Stripper

Unnamed "Mauve"
Devil Person
Female
Unknown
Bartender, Waitress

Unnamed "Mint"
- Devil Person
- Female
- Creator of Sleaze

Angie "Tangerine"
- Former Human, Devil Person
- Female
- Unemployed

Milton
- Devil Person
- Male, Straight
- Devil Tech Engineer

Legion
- Devil Person
- Male, Straight
- Bouncer

Vainglorious
- Devil Person
- GNC, Presumably Ace
- Artist
- Implied to be another child of The Devil

Xanthe Justice (last name: 2013-03-04)
- Human, White
- Female
- Granddaughter of Nana
- Around 16-18**

Nana Justice "Yarn Lady"
- Human, White
- Witch
- Female, Presumably Straight
- Baker, Grandmother

Clio Mirembe (last name: 2014-02-04)
- Human, African-American
- Female
- Hacker
- Around 16-18**

Tess "MacGyver"
- Human, Possibly Asian
- Female
- Mechanic, Engineer

Unnamed member of Sisterhood, "Li'l Sis" / "Helmet"
- Human, Possibly Asian
- Female
- Suggested to be Tess's younger sister
- Underage, presumably 10-12

Unnamed Medic
- Human, Dark Skinned, Unknown Ethnicity
- Female
- Medic

Rogue Fembot "PX"
- Escaped Pleasure Android
- Freedom Fighter
- Created by Milton

Original Weaponized Fembot
- Deceased
- Assasin Android
- Created by Milton

Weapon F #1 "Fedora"
- Escaped Assasin Android
- Allied with PX & Weaponized Fembots
- Identified by Fedora & Trenchcoat

Weapon F #2 "Jackie"
- Escaped Assasin Android
- Allied with PX & Weaponized Fembots
- Identified by Bomber Jacket

Weapon F #3 "Capri"
- Escaped Assassin Android
- Allied with PX & Weaponized Fembots
- Identified by Capri Jeans

Unnamed Fembot "Friendbot"
- Escaped Pleasure Android
- Allied with Lady Liberty
- Identified by Jacket & Boots

Hovering Fembot
- Service Android
- Working Deviltech Customer Service
- Identified by Heart Bodice

Robomf Fembot #1 "Poncho"
- Escaped Pleasure Android
- Waitress
- Working for and allied with Aunt Kate***
- Identified by Poncho/Shawl

Robomf Fembot #2 "Flutterbot"
- Escaped Pleasure Android
- Maid
- Working for and allied with Aunt Kate
- Identified by Boat-Neck Sweater

Robomf Fembot #3 "Vee"
- Escaped Pleasure Android
- Bartender
- Working for and allied with Aunt Kate
- Identified by V-Neck Sweater & Hat

Lilith
- Human, Seemingly white
- Witch
- Female
- Straight
- Li'l Evil's Mother

Li'l Miko "Minique"
-Human, Asian-American
- Female
- Forum Admin, Fangirl
- Underage, presumably 12

Theo
- Human, Possibly Asian
- Male
- Artist, Fanboy
- Underage, presumably 12

Francis Sebastian (last name: 2013-09-11)
- Human, White
- Male
- Gay
- Has unnamed boyfriend

Storytime Zombie
- Former Human, Zombie
- Male
- Unemployed

Ezekiel
- Angel
- Male, Presumably Ace
- Agent of God

Ariel
- Angel
- Female, Presumably Ace
- Agent of God

Amber
- Human, Unknown Ethnicity
- Female, Presumably Straight
- Works Hell TV Advertising Department

* this information was available on a now defunct and unavailable character page, only accessible through the wayback machine
-- slick, crim, squig, and seymour all attended college together in the earliest version of sinfest published for UCLA in 1991
--- also, slick had a girlfriend known as skids that he had been seeing long enough for the two to have an anniversary. they are no longer together by the time of publication of sinfest as a webcomic.
** this information is deduced from their (occasional, in the case of xanthe) use of 2 wheeled motorcycles and setting (you have to be about 16 or 18, depending on the state, to ride a motorcycle. sinfest takes place in the USA)
*** aunt kate is sinfest's interpretation of the greek goddess hecate/hekate, for this reason she is not included in this version of the character chart