Despite its importance, teaching isn't seen as a very prestigious job. Teachers don't get paid well and don't get much respect either. So it's notable when an exceptionally skilled person 'settles' for a lame old teaching job.
This character is a high school teacher or college professor who has skills beyond their job which are more relevant to the plot. If they're a science teacher, they might have invented the cure for cancer. Or they're a music teacher who was once a world-class concert pianist. Or maybe their talent is in something completely unrelated to the subject they teach, like treasure hunting, demon-slaying, or martial arts. Regardless, the teacher is a Hidden Badass who has hidden their badassery behind a desk.
Reasons for spending their days in the humble art of education vary. The teacher might be keeping their skills a secret, Living a Double Life where they moonlight as something much cooler. They might have been a Veteran Instructor who was disgraced or otherwise forced out of their previous profession. Or they may simply have a passion for teaching.
This character archetype is frequently paired with a particular stock scene where an important figure drops by their classroom unannounced, often in the middle of a lesson, to request use of said talents in a more high-stakes setting.
Typically, and especially when they are the protagonist, this character does very little actual teaching that the audience gets to see.
This trope does not discriminate between personality types or teaching styles. A teacher can fit into this trope whether they are a Cool Teacher, a Stern Teacher, a Sadist Teacher, an Absent-Minded Professor, or a Badass Teacher.
Compare with Almighty Janitor, who is usually more of a background character. This character is less powerful on average and almost always a protagonist or central character to the story.
Inevitably, using this trope shows an opinion on the teaching profession, either demeaning the job by suggesting that the character could do better, or celebrating it by suggesting that teaching is more valuable than any of the cooler things the teacher could be doing.
- Assassination Classroom: The mascot of the series is Korosensei, a bizarre hyperintelligent octopus-like creature who has threatened to destroy the world. Until then though, he's decided he wants to work as a high school teacher, teaching his class not just standard materials, but also assassination skills. While he could easily kill all the students with little effort, and they're all gunning for a bounty on his head, he proves to be an excellent teacher to them all, forming a general kinship and helping them improve themselves. It's later revealed that he was a human assassin who fell in love with the previous teacher of Class 3-E (before she died tragically) and that he himself will die for medical reasons in about a year. This gives him three reasons for finishing the students' education; he wants to memorialize/understand the woman he loved, he wants to do something truly good before he dies, and he's coping with his mortality by passing on his skills to the kids.
- At the end of the series, Nagisa continues this theme. He is a prodigy in the field of assassination and one of the last students of the best assassin in the world, but he is also a genuinely kind boy who hates conflict. So he does what Korosensei did for him by becoming a teacher to underprivileged delinquents, using his combat skills to protect himself from them and earn their respect.
- In Blue Exorcist, Mephisto Pheles is the headmaster of a school training exorcists...and also an incredibly high-ranking demon himself.
- Fate Series:
- Kayneth El-Melloi Archibald is a renowned mage of the Mages' Association and the Lord of the Department of Mineralogy of the Clock Tower. He is also a lecturer in the Department of Spiritual Evocation where Waver Velvet is one of his students. In Fate/Zero, he also participates in the fourth Holy Grail War where he is the Master of Lancer-class Diarmuid Ua Duibane. Initially, he was supposed to Rider-class, Iskander, but Waver stole it out of retaliation after being humiliated in class.
- After Kayneth died during the fourth Holy Grail War, Waver Velvet is adopted into El-Melloi family because the heir is too young to inherit the title. So, Waver is known as "Lord El-Melloi II" and becomes the Lord of the Department of Modern Magecraft Theory where he is also a professor. Despite his mediocre magecraft, he's reputed to be a great teacher who also cares for his students. During his spare time, he solves cases as detailed in his own story, Lord El-Melloi II Case Files.
- Gokusen: Kumiko "Yankumi" Yamaguchi is a high school math teacher who handles a class full of delinquents. She is also the granddaughter of one of the most powerful Yakuza bosses in Japan who is set to inherit her grandfather's position. The school principal knows her background which is one of the reasons he hired her because he knows she can take care of the school's most troublesome students.
- The eponymous Hell Teacher Nube is one of the most powerful exorcists in the series due to his Demon Hand. But even though many less-skilled mediums have used their talents to gain fame and money (such as Izuna and Mugenkai Jiku), Nube works as a simple elementary school teacher due to his love for his students.
- In Moriarty the Patriot, Professor William James Moriarty is a mathematics professor at Durham, while also masterminding the entire Lord of Crimes organization and plotting The Perfect Crime over and over to change Britain. While he does appear to genuinely love teaching, he is also using the opportunity to steer the next generation of elites in a more wholesome direction.
- My Hero Academia: being licensed as a Pro Hero can open the door to many lucrative opportunities. Top Heroes like All-Might, Endeavor and Sir-Nighteye can afford skyscraper headquarters and employ dozens if not hundreds of employees, even before taking into account their sidekick heroes. However, many heroes eschew that life, with several top Pro Heroes like Midnight and Eraserhead preferring to teach at UA. All-Might himself opts to take up a teaching job at UA shortly after the series begins, partially because he realises that his secret injuries are slowly catching up to him and he wants to pass on his ideals on to the next generation. When All-Might shows up for his first day of teaching, he finds journalists camped out around UA calling out to ask why he's chosen to take up teaching and whether this will affect his Pro Hero work.
- Naruto: Becoming a ninja requires that you attend the Ninja Academy, and upon graduation, students will be assigned an elite Jounin to serve as their personal mentor as part of a small team. The main characters get Kakashi, a legendary ninjutsu expert considered so dangerous that the assassination squad of at least one enemy nation had a "kill on sight" standing order against him.
- The protagonist of Negima! Magister Negi Magi, Negi Springfield, is tasked by his own school to be the teacher of a bunch of junior high girls... at the age of ten. Negi also happens to be a brilliant (if underpowered at first) mage on a personal quest to become a powerful mage and find his father. While the first few arcs center around the school (the second major arc is centered around the School Festival), the final arc takes place over summer vacation and pushes the teacher aspect of his character completely into the background.
- Soul Eater: Most of the teachers at DWMA are also Living Weapons or wielders of those weapons, which makes sense since that's the main subject taught there. The school is so powerful that it has its own paramilitary forces, and most of the witch and demon-fighting skills learned by its alumni wouldn't be useful in any other organization.
- In Tengen Toppa Gurren Lagann, Yoko spends several years using a pseudonym working as a teacher on a small, remote island to get away from her identity as one of the heroes of Team Gurren who saved all of Earth. Her secret comes out when the small village is attacked and she saves everyone.
- Early on in The Amazing Spider-Man (J. Michael Straczynski), JMS decided that Peter Parker should be more grounded and be more involved in his local community, so he starts work as a science teacher at a New York public school. Amongst the issues he must deal with as Spider-Man are thwarting a school shooting, tracking down kidnapped kids, and discovering that one of his students is a dangerous and murderous mutant (who instantly realises that Mr. Parker and Spider-Man are the same person because they have the same voice) note . Another awkward episode for him is when the kids learn that he is famous for taking pictures of Spider-Man and they are more interested in that than listening to his lesson.
- When he reveals his secret identity, it becomes even harder for him to be an effective teacher, as students are naturally more interested in his adventures while parents and fellow teachers are terrified of the attention he'll bring from supervillains and criminals seeking payback.
- Black Lightning has its titular superhero, whose civilian identity is Jefferson Pierce, a star athlete and Olympic gold medalist who chose to give up a bright future as a sportsman to qualify as a teacher. He became a high school physics teacher and principal in the notoriously poverty-ridden Suicide Slum where he grew up, hoping to do some good as an educator. He's first introduced using some of his skills to demolish some street gang heavies that were threatening the school. He becomes a superhero after realizing that beating up gang members as Jefferson Pierce wasn't enough to protect his students (and made them a target for retaliation).
- In Stormwatch PHD, Black Betty is one of the best-trained magic-users in the WildStorm universe, but, prior to being recruited by the Post-Human Division, spent most of her time as a Professor of Metaphysics, as she knows enough about magic to know that actually casting spells would require sacrifices that she's just not willing to make.
- A central premise of the X-Men is that they are a superhero group working out of a private school, and the older members usually work as teachers. Most of the staff are mutants with superhuman powers, some of whom have literal godlike powers; most are combat veterans; more than a few are geniuses in various scientific fields. The school itself is regularly a target for supervillains, terrorists, alien invasions, demonic invasions, and more, but luckily the teachers are usually capable of handling them.
- Miraculous Ladybug fanon commonly depicts Adrien as becoming a physics teacher after the events of canon. This is because it would suit his intelligence, extroverted personality, and (likely) desire to be distant from the famous career his Stage Dad forced him into. Whether he is still a costumed superhero depends on the fic.
- In Remnant's Bizarre Adventure, Jotaro Kujo teaches the history of the Frontier to the students of Beacon during the lead up to the Vytal Festival. Like the rest of Beacon's staff, he is a trained and professional Hunter. He's also one of the Frontier's strongest Hunter, possesses the powerful Stand Star Platinum, and is feared by the criminal underworld thanks to him defeating DIO years before the story started.
- In Legend of the Guardians: The Owls of Ga'Hoole, Ezylryb is a war hero and Shell-Shocked Veteran. Eventually he no longer wanted anything to do with war, so he became a flight teacher. Luckily, he's still more than good enough to save his students when they get ambushed, and said students respect him for who he is.
Soryn: [heartfelt; refuting Metal Beak's mockery of Ezylryb] He's my teacher.
- Louise Banks from Arrival is a linguistics professor who once served as a military translator, and is recruited by the government to help translate alien languages.
- Peter Venkman, Egon Spengler, and Ray Stantz all start the original Ghostbusters as professors of parapsychology at Columbia. Egon in particular, with his ability to invent ghost traps and weapons, has skills better suited to ghost-busting than teaching.
- Erin Gilbert from the 2016 reboot once worked as a supernatural physicist before the start of the film, trying to prove that ghosts exist. However, she later abandoned the project and disavowed it as nonsense in order to accept a teaching job at Columbia. When her old colleague Abby Yates published her work without her knowledge, it leads to Erin losing her job. However, it all works out for the best when she goes into the ghostbusting business with Abby and becomes more successful than ever before.
- Indiana Jones: Throughout the series, Indiana Jones works as an archaeology professor, a job from which he takes many lengthy leaves of absence to adventure around the world and save powerful magic artifacts from bad guys.
- In 11/22/63 and its television adaptation, the story follows high school English teacher Jake Eppings, who, in his journey into the past to prevent JFK's assassination, takes on his same job to pass the time and pay the bills. In the process, he befriends his coworkers and the students, as well as becoming smitten with another teacher, and though they have some suspicions about his behavior (such as hiding what he did before becoming a teacher or not being racist), they're none the wiser. Likewise, when he returns to the present, his students clearly see that he's distraught, but he refuses to tell them why.
- Mr. Krupp in the Captain Underpants series turns into the eponymous hero when someone snaps their fingers around him. As a teacher, he is a Dean Bitterman, while as a superhero, he is a Flying Brick (though also an Idiot Hero who George and Harold must save from danger as much as he saves them). Because of his Alternate Identity Amnesia, he has no idea this is the case.
- The Guild of Assassins' School is staffed by some very scholarly, capable people often possessing more letters after their name than are actually in the name. A casual observer might wonder if they're doing it for the grace-and-favour full board accommodation more than the money. Then the same casual observer might reflect that they are also Assassins. Who tend to be exceedingly well rewarded for their main job.
- Susan Sto Helit, who is a powerful supernatural entity, but doesn't want to be, and prefers teaching because it's "normal". Which doesn't stop her from using her abilities to make the lessons more interesting.
- Ryland Grace from Project Hail Mary is a high school science teacher who had long since left his own molecular biology research behind after his ideas on the formation of life without water got him laughed out of academia. However, his ideas prove to be correct after the discovery of alien life-forms called Astrophages that threaten to eat the sun. Grace is recruited by the governments of the world to help find a way to stop the creatures and save the world.
- Harry Potter:
- Albus Dumbledore is one of the most powerful wizards in the world, and people wonder why he chose to become headmaster of Hogwarts rather than something more powerful like Minister of Magic. Besides a love of children and learning, we learn later in the series that Dumbledore never trusted himself with power after he caused the death of his sister. The middle aged version of the character in the Fantastic Beasts film series probably fits this trope better because he's still teaching and more directly involved with the action due to being in his prime.
- Severus Snape, the potions master, is also a strong example. A genius potion inventor and formidable former Death Eater, it is revealed late in the series that he became potions master to act as a double agent, protecting Harry from Voldemort's inevitable return as an act of repentance for his role in Lily Potter's death.
- Honor Harrington, during her stint of teaching at the Royal Manticoran Naval Academy in Ashes of Victory. It's easier to list the titles and honors she hasn't received at that point in the series. She's 'merely' a full admiral rather than Admiral of the Fleet, isn't Countess White Haven, isn't captain of HMS Unconquered, and has turned down the Parliamentary Medal of Honor.
- In Percy Jackson, the centaur Chiron poses as a social studies teacher named Mr. Brunner to observe Percy. Throughout the series, various counselors at Camp Half-Blood are famous and powerful figures from Greek mythology, such as Dionysus, Tantalus, and Daedalus.
- Sherlock Holmes: Moriarty is a mathematical prodigy and the author of two fictional theses (one of which earned him a university chair) but he currently works as an army coach (a private tutor for officers). Holmes doesn't say what the scandal was that got him kicked out of the university, but he points out that his furnishings are far more expensive than his salary should allow as a clue that he's an Evil Genius.
- Jaime Sommers, The Bionic Woman, is a Secret Agent for the Office of Scientific Investigation. Her undercover identity is a school teacher at the Ventura Air Force Base, assigned to a class of "difficult" students. Her first day there, Jaime calmly tears a California phone book in two while introducing herself. This becomes an Aborted Arc by the second season.
- Walter White from Breaking Bad was once almost a massively successful scientist, but when his partnership with his old friend Elliot Schwartz fell through, he wound up stuck as a high school chemistry teacher in Albuquerque. He's overqualified for the job, and that blow to his ego is part of what pushes him to start cooking meth. Word of God is that Walt was the one who ended the partnership and part of his bitterness and resentment stems from knowing, deep down, that he had the success that he wanted and just threw it all away out of pride. Indeed, he turns down another opportunity to work a much higher-paying job that matches his skill-set because he views it as charity from his former partners.
- Doctor Who:
- In the first two seasons two of the Doctor's companions are schoolteachers. Whilst Barbara's skills aren't that unusual for a history teacher (though she is virtually the only companion the Doctor ever treats as an equal), Ian is clearly quite skilled in hand-to-hand combat.
- In "Human Nature"/"Family of Blood", John Smith is a typical teacher at the Farringham School for Boys in 1913 England... who happens to look suspiciously like the Doctor and has dreams about the Doctor's life. In fact, he is the Doctor, but used a device that overwrote his memory and brought him down to normal in order to hide from antagonists. John Smith doesn't actually know he is this trope, resulting in a Tomato in the Mirror moment for him when Martha needs to bring the Doctor back to defeat the antagonists.
- Companion Clara Oswald takes up a teaching position between Series 7 and 8, and continues to hold this position for two series while living a double life as the Doctor's companion. This causes issues in her budding relationship with Danny Pink, a fellow teacher who himself used to be a soldier, a background which becomes relevant when he takes control of the Cyberman army at the end of Series 8.
- "The Pilot" opens with the Doctor living under the guise of a human university professor for decades, where he takes an interest in Bill Potts. It is later revealed he took the job to watch over his enemy Missy, who has been trapped in a vault under the school the whole time.
- Daimon Helstrom from Helstrom works as an ethics professor while also hunting demons and sporting some demonic powers of his own.
- Instinct has Dylan Reinhart, a renowned author and professor of psychology at the University of Pennsylvania. Unknown to most, he was also previously a case officer and analyst for the CIA and has paramilitary training.
- NUMB3RS features Charlie Eppes, a former child prodigy who teaches applied mathematics at the California Institute of Science. Unknown to everyone, even his own brother who works with the FBI, Charlie has top security clearance and routinely consults for the CIA.
- Power Rangers: Dino Thunder: Dr. Tommy Oliver appears to be a simple high school science teacher. In actuality, he is the Black Dino Ranger and has been a Ranger for a long time.
- The Secrets of Isis: High school science teacher Andrea Thomas went on an expedition in Egypt, where she discovered a magic amulet that endows its wearer with the powers of the goddess Isis. By reciting "O Mighty Isis," Andrea Thomas transforms into a superhero who rescues those in distress and thwarts villainy.
- Star Trek: Enterprise: Before she got her job on the ship, the linguist Hoshi Sato was a language teacher. She's a prodigy and can speak around 40 languages.
- Ultraman Leo features the titular hero's human identity, Gen Ohtori, who works as a gym coach and tutor at times of peace. He's also a Big Brother Mentor to the Umeda siblings, two orphaned children, and more often than not risks his life for his pupils.
- Ultraman 80 has Takeshi Yamato, the human disguise of the titular character, who despite being a several millennia-old Ultraman from a distant galaxy assigned to protect Earth, is actually happy to assume the role of a class teacher for Sakuragaoka Junior High School in Tokyo as part of his civilian identity, even forming a rock band with his class in one episode and revealing his Ultraman form to cheer up a heartbroken student.
- Byleth from Fire Emblem: Three Houses is an accomplished mercenary nicknamed The Ashen Demon. Despite being skilled enough to single-handedly turn the tide of a war, they mostly keep their head down and teach at Garreg Mach Monastery, because they're an almost-Empty Shell whose symptoms are alleviated by being around children.
- In Hades, the ghost assigned to teach prince Zagreus combat is Achilles himself, one of the foremost heroes of Greek mythology. This narratively enables a sidequest centered on helping Achilles deal with his past.
- Jade Empire has a villainous example: Sun Li fled underground after a failed attempt to usurp his Emperor, taking on the identity of a rural martial arts teacher. Besides making money and shielding him, this choice gave him a perfect excuse for molding The Chosen One he'd kidnapped into a catspaw who would do what Sun Li couldn't.
- The Legend of Heroes: Trails of Cold Steel: As Thors Military Academy is, well, a military academy, several of its instructors, the principal, and even the school nurse are all Veteran Instructors with a wealth of combat experience they're more than willing to demonstrate when the school itself comes under attack near the end of the first game, much to the surprise of the attacking army. It's not just the teachers with actual military background, either; the science instructor is highly proficient with Orbal Arts and once interned under the most brilliant inventor in the country, while the history instructor is actually the Second Dominion of the Gralsritter working undercover, and one of the most powerful and informed people on the continent.
- In Fate/stay night, Taiga is a Yakuza's daughter who was too irresponsible to go into that profession (the organized crime of Japan is very organized), and too rebellious to compete in official kendo tournaments like she wanted. So now she teaches kendo at a high school, mooching off of her wealthier students and the stipend her family sends her. (She also helps her family dispose of certain materials, which is why Shirou always has so much junk to practice magic on.) Given that Taiga is also a compassionate person- in her own way- who'd rather play with kids than corrupt them, this was probably for the best.
- RWBY: Beacon Academy's history teacher, Dr. Oobleck, lampshades the fact that all Academy teachers are Huntsmen by explaining why he feels being a teacher is more important than being a Huntsmen; putting knowledge of how to fight and survive the Grimm without repeating the mistakes of history in future generations is extremely important. His boss, Beacon Academy's headmaster, Professor Ozpin is the living example of Dr. Oobleck's message. An immortal warrior-wizard, Professor Ozpin has been secretly fighting the equally immortal Salem. She controls the Creatures of Grimm and is trying to destroy the world to free herself from a divine curse; his divine mandate is to save humanity, and he taught the world how to fight back against the Grimm. As they're ex-lovers, she's Never My Fault and he has a Guilt Complex, they've been stuck in a rut for millennia — trapped by their history instead of learning from it.
- In Phineas and Ferb, Doofenshmirtz is the future inventor of time travel and an aspiring Evil Overlord, at which he is not good enough to pay his bills. So he works as a substitute science teacher, something he unexpectedly enjoys because it gives him a captive audience he can rant to and he gets to spend time with his beloved daughter.
- In the Rick and Morty episode "One Crew Over the Crewcoo's Morty", Rick and Morty recruit Mister Poopy Butthole for their heist team. Mister Poopy Butthole works as a college professor, and they visit him in his lecture hall, where he displays his deadly training in martial arts.
- In post-series material for Transformers: Animated, Arcee is revealed to have gone back to teaching (her profession before the war). She spent part of the war as an intelligence officer and fully retains those skills, as shown when she and Sari foil the efforts of a Decepticon doomsday weapon.
- In France, due to the high number of scholars who studied at the Higher Normal School, several intellectuals taught at high schools (lycées) as agrégés, such as Aime Cesaire (letters), Simone De Beauvoir, and Jean-Paul Sartre (both in philosophy).
- Bob Moses, a civil rights activist, MacArthur genius grant recipient, and holder of a philosophy PhD from Harvard, decided to teach math at his daughter's public high school when he learned they did not offer algebra classes. He regarded this as an extension of his activism, since he regarded the lack of algebra education in poorer, majority-Black communities as perpetuating their inequality.