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"Shut the f*ck up! Your teacher will be here in a minute."
— Steinbeck to Cody.

Principal Steinbeck is a minor character, the cruel and somewhat insane principal of Junior's school and the archenemy of Junior. He loves it when the students get into trouble, so he can punish them. It is unknown why Principal Steinbeck is evil and how he became that way. He is very abusive and mean towards the students, but he appears to be nice and smooth-talking towards other adults, including the teachers. He made his debut as the main antagonist of Junior's Homework, the main antagonist of Junior's Summer School, the secondary antagonist of Junior's 1st Grade!, and the main antagonist of  First Day of School!

However now that SML has been family friendly since 2019, he might not return ever again.


Principal Steinbeck was born on April 22, 1978. During his childhood he loved Doofy O's and possibly watched Doofy The Dragon which must have made him a psychopath. At some point, he became the Principal of his school.

In "Junior's First Grade Part 4" Principal Steinbeck has a conference meeting with the students and their parents. He says that they goofed up after enrolling Mr. Winkle as the new teacher. Bowser gets angry with him and asks why they didn't know he was a pedophile and thinks they didn't do enough background checks. Principal Steinbeck responds by saying that they tried everything but has Officer Goodman explain the rest. As Goodman says that Mr. Winkle called him "hot" Principal Steinbeck remarks that he called him "hot" too and started to bicker angrily. After Joseph's Mom reveals they need more "Windex", Joseph remarks that that's not what was going on. Steinbeck laughs evilly and says that the next replacement teacher will be perfect.

In Part 5 of the 1st Grade series, Bowser Junior answers the door to their apartment and sees Principal Steinbeck. He explains that he needs to see Bowser. So, Junior goes to Bowser's room and tells him that Steinbeck needed to see him. Then, Principal Steinbeck tells Bowser that they'll let Junior pass 1st grade and says that 2nd grade won't be easy.

He returns once more in First Day Of School, where Principal Steinbeck barges into the classroom and tells the students that if they fail, he'll punish them in the worst way possible. Cody asks when the teacher would arrive, but Steinbeck tells him to shut up. Afterward, he leaves the classroom.

However as of now, It’s currently unknown what happen to him, maybe he was fired mostly due to his behavior or has been arrested due to his threats.

Criminal Record

Likes and Dislikes


  • Students failing classes
  • Punishing and terrorizing students
  • Jackie Chu (Formerly)
  • Doofy O's
  • Doing evil laughs
  • Threatening and abusing students



See /Quotes


  • He wore a hat in Bowser Junior's 1st Grade! Part 4. He also wore a different suit in First Day of School!
  • According to some fans, he is similar to The Joker from Batman.
  • He is somewhat similar to Mr. Krupp from the Captain Underpants series. Because he is a mean principal, Steinbeck is also a lot similar to Principal Greedyguts from the Canadian animated series Jacob Two Two.
  • In his first two appearances, he has a slight British accent, but in later videos, his accent sounds more American.
  • He is named after John Steinbeck, an American book author and the winner of the 1962 Nobel Prize in Literature.
  • Despite his insane and abusive disposition, Steinbeck is not completely evil, as he shows an intense dislike for pedophiles, because in Bowser Junior's Summer School 7, he calls the police when Bowser Junior told him he was being molested by Chef Pee Pee in the men's bathroom.
  • He is believed by fans to be Charleyyy in disguise. This makes sense because of his ability to get along with Bowser so easily.
  • It is revealed in Bowser Junior's 1st Grade! Part 5 that he liked to eat Doofy O's as a kid and is possible he watched Doofy The Dragon which possibly made him learn to be a psychopath. 
  • It is hinted, yet unconfirmed that he is Joseph's dad, because in Bowser Junior's 1st Grade! Part 1, Joseph says that his mother sleeps with him.
  • "Steinbeck" could possibly be a pun on "stand back" as seen in Bowser Junior's Summer School when he writes "Steinbeck" on the chalkboard, telling the class to "Steinbeck."
  • It’s unknown if he will make a comeback in the series as he has not made any newer appearances since First Day of School!.


Polls have been archived. See here for poll archive. Polls have been archived. See here for poll archive.

Main characters MarioBowserChef Pee PeeBowser JuniorJosephCodyRosalinaJeffyBrooklyn T. Guy
Recurring characters GoodmanJackie ChuTyroneJudyRichard GoodmanBully BillSuper DBlack YoshiShrekGod
Minor characters Doofy The DragonToadCharleyyyTony The TigerWoodyMargaretLuigiCraig The DevilScrewballMr. PigPeachThomasKenPatrickPink YoshiPrincipal SteinbeckHarold WilfredBanzai BillDonkey KongDiddy KongGolden ThomasHanselKirbyChris the CucumberFelipeThe RatEmily ColemanPixie GoblinSamanthaWarioWaluigiSimmonsBrooklyn Guy's WifeTyreeseTom BradyMr. WinkleCarlosCandyCandy's FatherMickey MouseRay CheesyD-Money JuniorJackie TwuMine! BirdScooterLoan DolphinSonicChef Poo PooChompyThe AlienDr. Fredrick FinkleshitsJacques Pierre FrançoisCrystalHarambeBarack ObamaMr. DinkleThe Alien's WifeTerranceMelvinDoes Bad Things GuyGumboDrawing JeffyMr. MagooCookie Monster
One-Time characters Dark Matter in my ShortsChef LuigiThe CrocodileElectrician's SonJoseph's GirlfriendRemySheila PerkinsPopeyeD-Money SeniorThe Cat In The HatDoofy's Ex-WifeBirdoPolly The ParrotKidnapperKatyJoseph's DadMr. BonesFeebeeJeff The KillerKiller ClownOther Killer ClownChazJunior JuniorStephen HawkingPee Pee SuckWormyNancy JeffyEaster Bunny GenieRussian SpyPiggieGreen Bean GiantPoofGreg the PigDewey DonediditCatherine CatfishBungholeShelbyKool-Aid ManBearySharkyBabiesBig BwahBoofy the MooseChester the ChickenMore...
Classic Characters Big RedKung PowBaby PeachThe RatTyreeseTaco Bell ChihuahuaMama LuigiSpeedyPimpster GoombaSkittlesShrek JuniorTalibanBlueChadKing PigRay the pigHelmet PigYoshiCeciliaKing StrongbottomTannerKoopa TroopaAtsoBrown ElephantLazlo
Cast Logan ThirtyacreLovell StantonLance ThirtyacreChris NethertonChilly JimenezElaina KeyesTito JimenezAnthony MillerMatthew ReberJulian JimenezDonald RodriguezRebecca
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