Geraldine Antonia "Jerri" Blank (Amy Sedaris)
- "Hello, I'm Jerri Blank. Thirty-two years ago I dropped out of high school and ran away from home. Oh, I made a lot of friends... did a lot of time. I was a boozer, a user and a loser. I stole the TV... Did some more time. But now I'm back in school! And though the faces may have changed, the hassles are just the same."
- Anything That Moves / Depraved Bisexual: "I like the pole and the hole". Also, all of her love interests are teenagers, not to mention her past with Ramon the Mule.
- Beauty Inversion: As you can see from her page picture, Amy Sedaris is actually quite dishy.
- Catchphrase: "I've got somethin' t' say!"
- Criminal Procedural: Frequent references are made to Jerri's delinquent past, which heavily influences her actions during the show.
- Friend to All Living Things: Jerri has a new pet every episode of Season 1, which always dies a horrible death by the end.
- Gonk: Jerri is about as close to being one as is possible for a live action show.
- Hartman Hips: Jerri's hips are out of proportion to the rest of her body. Mr. Blackman says when Jerri goes on a hunger strike:"Are you joking? She could live off stored fat. Her hips alone could take us into the next semester!"
- Hollywood Pudgy: Numerous comments are made about her being obese despite being fairly petite.
- Hypocritical Humor: Being omnisexual does not keep Jerri from flinging around anti-gay comments. Nor does having Native American ancestry get in the way of her racism.
- Incest Is Relative: Jerri discovers the transfer student she likes is actually her long-lost son. This discovery doesn't deter her from asking if they can still make out.
- Kavorka Man: A rare female example—although not always successful in her pursuits, she has many more guys and girls of the week than her... unique appearance can account for.
- Missing Mom: According to Sara, Jerri's mother died shortly after she ran away from a broken heart. Also is one to her son, Ricky.
- That Makes Me Feel Angry: Jerri has a tendency to state how she's feeling directly.
- Suddenly Ethnicity: The third season reveals that Jerri is Native American.
- Tomboyish Name: They specifically wanted a name for the character that would come with the same nickname as a man's. Antonia —> Toni was the other front-runner and survives as her middle name.
- The Unfavorite
- Unsympathetic Comedy Protagonist
Sara Blank (Deborah Rush)
- Oh Jerri, I didn't know you were coming home this early. We would've left sooner.
Jerri's prim and proper stepmother. She was not at all happy when Jerri returned home, and always seeks to make her feel as unwanted and unloved as possible.
- Commuting on a Bus: A regular in Season 1, and a frequent recurrer afterwards.
- Elephant in the Living Room: Like everyone else, Sara treats Jerri as if she was a real (and unwanted) teenager, and very rarely acknowledges that she is the same age as her. It gets even stranger after her husband's death where she could easily kick Jerri out but continues to let her live with them.
- Parental Favoritism: Openly and purposefully shows more affection for her biological son.
- Passive-Aggressive Kombat: A seasoned master.
- Politically Incorrect Villain: For a certain measure of villain— she is probably the most open in her racism of all the characters.
- Wicked Stepmother: This goes without saying.
- White-Dwarf Starlet: In her youth, Sara was a stage actress who performed as Peter Pan. She gave up her career to start a family and still yearns for the life she left behind.
Guy Blank (Roberto Gari)
Jerri's elderly, immobile father.
- Demoted to Extra: Part of the main cast in Season 1, and recurring in early Season 2 before being...
- Killed Off for Real
- Racist Grandpa While Jerri is looking through his closet to find information on him after his death, you can clearly see a Klu Klux Klan robe. He had stipulated that he wanted no "darkies" to attend his funeral. Of course, we never see any racist behavior from him, as he is...
- The Voiceless: And The Motionless—he is only ever seen in silent mid-action.
- The Other Darrin: In The Movie.
Derrick Blank (Larc Spies)
- I'm gonna go masturbate."
Jerri's half-brother, the son of Sara and Guy, who also attends Flatpoint High.
- Ambiguously Gay: He watches gay porn with other bullies "to get our hate back". In one episode Mr. Jellineck shows up to their house in a speedo saying he's here to see him.
- Commuting on a Bus
- The Favorite
- Jerk Jock
- Little Brother Bully
- The Other Darrin: In The Movie, due to Larc Spies no longer looking the part.
Onyx Blackman (Greg Hollimon)
- "I'm an obtuse man, so I'll try to be oblique."
Principal of Flatpoint High. Blackman is more like a tyrant than a school administrator. Portraits and other portrayals of him can be seen in various places in the school, including the bathrooms.
- Bald, Black Leader Guy
- Large Ham
- Malaproper: See the quote above.
- Meaningful Name
- Scary Black Man
- Selective Obliviousness: Principal Blackman remains unaware that Noblet and Jellineck are lovers no matter what they say or do in his presence, even after he catches them together in the boiler room, and Jellineck has his pants off.
- Why Did It Have to Be Snakes?: Greg Hollimon has a strong phobia of drowning. Making the brief shot of him canoeing in the school pool in the background a hard scene for him to perform.
Chuck Noblet (Stephen Colbert)
- ""No one makes friends with a failure. Okay? Understand?"
Teacher of history and English, editor of the school newspaper, and assistant to the principal. Perhaps all these responsibilities, his tendency to burst into tears, and his obsession with food are symptomatic of dealing with his gay affair with Geoffrey Jellineck.
- Armoured Closet Gay: Has a wife and a child at home, and goes out of his way to pretend Geoffrey is nobody to him in public.
- Big Eater
- Coming-Out Story: Subverted in "Hit And Run", but it would have been straight if he hadn't chickened out.
- Sadist Teacher: Has a particular hatred for Jerri. Among many incidents between the two, in one episode Noblet says to Jerri, "Now I know you're upset, but it's been two days! You need to move on." Two days after her father was abruptly mauled to death by loose vicious attack dogs.
- "Jerri, I was going to tell you this in privacy but I didn't think it would be suitably humiliating enough. You failed Jerri. You failed. You are a failure."
- Straight Gay
- Yaoi Guys: With Jellineck.
Geoffrey Jellineck (Paul Dinello)
- "Yes, maybe that's true. But do they care about me? I don't think so. Do you see the flaw in your logic now?"
Art teacher. Geoffrey seems to like the idea of being the artist more than, well, actually creating art. He's consumed with himself to the point that he twists other people's problems to be about him. The epitome of "But what about me?!"
- Attention Whore
- Cool Teacher: Geoffrey very much thinks he is this. The students do not agree.
- It's All About Me
- "I can't reach her. She is lost in some frightening world that isn't centered around me."
- Its Pronounced Tro PAY: Do not call him "Jeffrey".
- The Obi-Wannabe: Geoffrey is the only adult who is usually nice to Jerri and gives her advice, but only at his own convenience and to stroke his ego.
- Pastimes Prove Personality: Geoffrey is an artist. Unfortunately, he's not actually very good at it.
- Terrible Artist: Most of his artwork looks like this, at best.
- Apparently he does not like seeing art better than his. In one episode, he rips up a realistic drawing of a turkey a student made and draw a turkey he made by tracing his hand
- Yaoi Guys: with Noblet.
Cherri Wolf (Sarah Thyre)
- "...and smack it, smack it, smack it. OK, I'm done."
The gym teacher at Flatpoint High, the only regular teacher besides Noblet and Jellineck.
- Butch Lesbian: Played with—despite being the target of lesbian jokes, she is normally presented as straight.
- Becoming the Mask: She genuinely falls in love with Jellineck during their pretend marriage for a school project. He... does not feel the same way.
- My Girl Is Not a Slut: Has this attitude towards herself—claims to be a virgin despite at the very least clearly having a sexual encounter with the chef at her second job.
Cassie Pines (Janeane Garofalo)
- ""Just because your dad was killed in some freak accident nobody can have one!? Well, I'll tell you something. My daddy's alive and yours is dead and ain't nothing gonna change that!"
Orlando Pinatubo (Orlando Pabotoy)
- Butt-Monkey: The most frequent target of Jerri's racist comments.
- The Danza
- Horrible Judge of Character
- Only Sane Man
- Unlucky Childhood Friend: Has a crush on Jerri in Season 1.
Tammi Littlenut (Maria Thayer)
- Entendre Failure: Jerri is constantly coming on to her, but she either ignores or misunderstands her comments.
- Naïve Everygirl
- Only Sane Woman
- Teacher/Student Romance: Tammy is in a committed and very open relationship with the school science teacher, to the point of being Sickeningly Sweet Hearts. The rest of the school thinks it's sweet though.