Series 1–3 Alfred Prufrock "
Alfie"
Wickers (
Jack Whitehall) stars as a newly qualified history teacher of Class K. An incompetent but fun-loving teacher, he struggles for authority in his form. He has a crush on fellow teacher
Rosie Gulliver (
Sarah Solemani), a socially-conscious Biology teacher with whom he enjoys a will-they-won't-they relationship through most of the series. Alfie is good friends with headteacher
Shaquille Banter "
Simon"
Fraser (
Mathew Horne), the school’s eccentric, laidback and incompetent headteacher who invests the school's money in unprofitable schemes. While Alfie enjoys a good relationship with Fraser, he clashes with the school's deputy headteachers, beginning with the strict disciplinarian and fascistic
Isobel Pickwell (
Michelle Gomez), who fakes her death. She is replaced in Series 2 by
Professor Celia "
Pro Green"
Green (
Samantha Spiro), who begins a relationship with Alfie's father,
Martin Wickers (
Harry Enfield), who in turn replaces Green as deputy headteacher after they marry and Green leaves Martin destitute. The Class K pupils are: •
Chantelle Parsons (Nikki Runeckles), a sexually-suggestive pupil who teases Alfie. •
Jing Hua (
Kae Alexander), the most intelligent and serious pupil of Class K, of
Chinese descent, who grows to appreciate Alfie as a "good and decent man". She helps Alfie expose Pickwell's fraudulent expenses claims, and convinces Alfie to continue teaching at the end of Series 3. •
Joe Poulter (
Ethan Lawrence), Alfie's closest ally, who willingly humiliates himself to help his teacher. He is the butt of jokes and pranks by other pupils, although they seem to have affection for him, and he grows in confidence by the end of Series 3. •
Mitchell Harper (
Charlie Wernham), the tough guy of Alfie's class, who pokes fun at fellow pupils and Alfie, who often retorts back. Mitchell shares a close, banterous friendship with Rem Dogg. Alfie and Mitchell develop their friendship in Series 2 and especially in Series 3, after Alfie successfully helps Mitchell impress Cleopatra, with whom Mitchell is infatuated. In the second episode of Series 3, Mitchell leaves Abbey Grove after his father's fairground is shut down by the council. He returns in "The Exam", in which he is shown in a youth detention centre. •
Leslie "
Rem Dogg"
Remmington (
Jack Binstead) is a pupil who uses a wheelchair. He comes across as a cheeky chap who pokes fun at Alfie, and is very close friends with Mitchell. In Series 3, he becomes an emo and rarely speaks. He becomes emotional when Mitchell gives him an impassioned goodbye, but is called "gay" in response, referencing their light-hearted relationship. •
Stephen Carmichael (
Layton Williams) is a camp, gay member of the class. He has a passion for fashion, dancing, musicals and films, and is best friends with Chantelle. In the Christmas special, he begins a relationship with Frank Grayson. He appears not to get on with Frank in Series 3, but Frank agrees to be his date for the prom and they are later crowned Prom King and Queen. He stuns others by breaking homosexual stereotypes, including being good at football and advanced martial arts. •
Frank Grayson (Jack Bence) is the school bully, who intimidates his fellow pupils as well as Alfie. At times, he appears to be insecure about himself, breaking down in Alfie's arms after Pickwell dies and exploring his sexuality in the Christmas special, culminating in a relationship with Stephen. Martin moves Grayson to Class K in order to avoid expelling him, which would have upset his new girlfriend, Grayson's mother. In Series 3, he appears no longer to get along with Stephen, but agrees to be his date to the prom and they are crowned Prom King and Queen. •
Cleopatra Ofoedo (
Weruche Opia) is introduced at the start of Series 3. She is aggressive and especially hostile to Alfie and Mitchell. She is black and sensitive to racial issues, frequently accusing others of racism. She agrees to make out with Mitchell, but still does not like him. After Mitchell leaves, she begins making jokes at Alfie's expense like Mitchell used to. Despite her hostility, she admits in the final episode that she likes Abbey Grove. Recurring characters include: •
Olive Mollinson (
Leila Hoffman, series 1 and 4), an elderly Art and Maths teacher. •
Preet van der Plessis (
Harry Peacock, series 1 and 3), a South African self-defence tutor who is arrested for attacking Alfie, and later returns to teach PE and declares his infatuation with him. •
Katherine Grayson (
Katherine Kingsley), Frank's mother, who begins a relationship with Martin after his breakup with Green. Grayson has a pedigree
chihuahua called Coco whom she considers a princess, showing more affection towards Coco than her son. Her relationship with Martin ends after Cleo may have unknowingly killed Coco while she was in Martin's care (Coco is later shown to be unharmed in the post-credit clip). •
Richard (
James Fleet, series 3), an ex-boyfriend of Rosie's, who becomes Alfie's love rival. •
Mrs Carmichael (Hillary Whitehall, mother of Jack Whitehall), Stephen's mother, a nurse. Other notable guest characters who were the focus of episodes included
India (
Phoebe Waller-Bridge), a drug counsellor; and
Kevin Schwimer (
Kyle Soller), a fraudulent history teacher who competes with Alfie for the affection of Class K.
Series 4–5 The special revival episode featured most of the original cast of pupils, with the exception of Alexander.
Bernadette Hoburn (
Vicki Pepperdine) is introduced as the blunt, strict new headmistress of Abbey Grove; Horne reprises his role as Fraser, but it is explained that he accepted a promotion to working in the school's kitchens. The episode introduced a new set of Class K pupils, and set the premise for Williams and Wernham to reprise their roles as Stephen Carmichael and Mitchell Harper in the fourth series, teaching Drama and PE. Hoburn navigates their rivalries and antics, as do the pupils with whom they compete for affection. The new Class K pupils were: •
Usma (Asha Hassan), the glamorous, social media obsessed gossip of the class. She is shown to be image-conscious, sassy and popular. She is partially based on how Stephen was portrayed in the original series; Williams said that he was consulted as part of the creation of the character. •
Blessing (
Francesca Amewudah-Rivers), a money-oriented member of the class who is always hustling and running scams which can sometimes get her into trouble with some of the teachers and other pupils. Blessing is often Mitchell's sidekick for his schemes. •
Inchez (Anthony J Abraham), an aspiring rapper who tries to project a front that he is cool, though the rest of Class K do not take him very seriously. •
Harrison (Bobby Johnson), a dim-witted but loyal member of the class. Due to his lack of intelligence, Harrison is always willing to go along with whatever plans his friends or his teachers suggest. •
Warren (Ali Hadji-Heshmati), a smart, quiet member of the class who prefers to keep to himself. He is conscientious and organised, meaning that he often ends up having to neglect his studies in order to help Stephen's latest efforts to become a star. •
Jemima "
Jinx" (
Laura Marcus), a socially-conscious member of the class who appears to be completely aware of her own privilege. Hoffman reprised her role as Olive Mollinson in a guest appearance in the fourth and fifth series while
Hilary Whitehall reprises her role as Stephen Carmichael's mother.
Bianca Del Rio makes a guest appearance in episode two. ==Episodes==