Ja'mie King

Ja'mie King, portrayed by Chris Lilley, is the main character of the show. She was also a main character in two of Lilley's previous shows, We Can Be Heroes and Summer Heights High. Ja'mie: Private School Girl follows Ja'mie in her final year of school, having left Summer Heights High and returned to Hillford Girls Grammar School.^[3]

Mitchell

Mitchell Ward, portrayed by Lester Ellis Jr., is Ja'mie's love interest. A new Year 10 student on a rugby scholarship who Ja'mie calls "totally quiche", at the boys' school Kelton Boys Grammar down the road.

Prefects

The Prefects are Ja'mie's friend group at school and the most popular clique at Hilford. They are self-described as the quichest girls at the school, "quiche" being a term made up by Ja'mie herself, meaning "a step above hot". All the girls are expelled at the end of episode 6 after they give a raunchy performance at the Hilford Presentation evening. They all enroll with Ja'mie at Blaxland College, shown in the 6-month skip.

• Madison Cartwright portrayed by Georgie Jennings; The most perfect prefect, is Ja'mie's best friend until episode 4. She falls out with her after Ja'mie learns she spent a free period with Mitchell which also led to a break-up between him and Ja'mie. Ja'mie tries to take back her prefect status and the two engage in a cat fight. In episode 5, she and Ja'mie make up after Mitchell sends a dick pic to Ja'mie and she lies to Madison about all these horrible things Mitchell said about her, leading to her dumping him.
• Olivia Harrington portrayed by Georgia Treu
• Imogen "Immy" Gallagher portrayed by Laura Grady
• Morgan Courtier portrayed by Phoebe Roberts
• Alexandria "Alex" Lupinski portrayed by D'arci Buckerfield
• Isabella "Bella" Mansouri portrayed by Tayla Duyal

Courtney King

Courtney, portrayed by Madelyn Warrell, is Ja'mie's younger sister who also attends Hilford. She is the subject of a lot of Ja'mie's abuse, particularly over her singing in the school choir. She and her friend Selena (Thi Reynolds) film Ja'mie's risqué dance performance with Mitchell.

Cody

Cody Bomhoff, portrayed by Alex Cooper, is Ja'mie's "GBF" (Gay Best Friend). He attends Kelton Boys Grammar and is the first to inform Ja'mie about the arrival of Mitchell. He takes dance class at Hilford with Ja'mie due to Kelton not having a class. He is responsible for Ja'mie's rebel makeover in episode 5 and he also accompanies her to visit Kwami for the last time.

Other characters

• Jhyll King, portrayed by Jhyll Teplin, is Ja'mie's mother (previously seen in We Can Be Heroes and Summer Heights High). She is still abused regularly by Ja'mie.
• Marcus King, portrayed by Brad Brivik, is Ja'mie's father who she often manipulates for her own gain. Ja'mie and her father have a very strange relationship.
• Mandy Bryant, portrayed by Monique Max, is Marcus' assistant who Ja'mie likes due to her being young and agreeing with Ja'mie's idea for a party. It's implied that Marcus is having an affair with her.
• Mr. Hayes, portrayed by Wayne Perkins, is the deputy principal of Hilford Girls Grammar. He may appear blind to Ja'mie ongoing nastiness however he isn't always completely oblivious. After threatening to expel Ja'mie in episode 5, he finally does so at the end of episode 6. After stopping Ja'mie's rant about the Hilford Medal, he is forced to intervene when Ja'mie plays the video of her and Kwami. He and Ms. Welham expel Ja'mie and the Prefects following their raunchy performance at the presentation evening.
• Ms. Welham, portrayed by Lise Rodgers, is one of the principals of Hilford Girls Grammar (previously seen in We Can Be Heroes and Summer Heights High). Unlike We Can Be Heroes and Summer Heights High where she appears to think highly of Ja'mie, she seems to have a very poor opinion on her. In episode 5, she is forwarded the raunchy video of Ja'mie and Kwami, which infuriates her and worries about the schools high reputation being damaged by the video. When Ja'mie and the Prefects do their raunchy performance at the Hilford presentation evening, Ms. Welham is last seen glaring at Ja'mie with fury from the audience. Both her and Mr. Hayes expel Ja'mie and the Prefects at the conclusion of the presentation evening.
• Lauren Nikolov, portrayed by Rose Flanagan is one of the "Boarders", a group of girls that Ja'mie refers to as fat girls and lesbians. She and Ja'mie have a mutual dislike of each other. In episode 3 she turns up at Ja'mie's party, and when denied access, insists that Ja'mie is fat herself causing her to have a brief meltdown.
• Erin Walker, portrayed by Brodie Dare, is another "Boarder". She is in Ja'mie's dance class and like Ja'mie she does charity work, a fact Ja'mie resents. In episode 5 it is revealed that she has won the Hilford medal causing Ja'mie much distress. In episode 6, she wins the medal and performs her dance at Speech Night, much to Ja'mie's disgust. It is mentioned after the 6-month skip that Erin has a boyfriend and she is supposedly getting married so she can have sex, due to her Christian values.
• Kwami Onwuatuegwu, portrayed by Albert Mambo, is a Ugandan boy who Ja'mie Skype-chats with every night. In episode 2 he sends a photo of his penis to Ja'mie. He moves in with the Kings in episode 3 and attends Ja'mie's party. In episode 5 he is kicked out of the King's home after Mr King discovers that he was showing his penis on Skype to Ja'mie as she was showing him her breasts. Ja'mie later visits him to explain why he was kicked out, revealing that she only used him to help her cause for the Hilford Medal. He claims that he loves her, however she rejects him and leaves. In episode 6, Ja'mie shows the video of her and Kwami at the Speech Night leading to her being expelled.
• Astrid O'Hara is Ja'mie's girlfriend. After Ja'mie gets expelled from Hilford Girls Grammar she starts going to a new school Blaxland College and goes through her "bisexual phase", and it is shown that Ja'mie often starts fights with Astrid and threatens to break up with her.
• Brianna, portrayed by Emma Clapham, was best friends with Ja'mie in We Can Be Heroes and Summer Heights High. Ja'mie states that she is no longer her friend because she became 'fat' and 'sorta indie'. In episode 5, Madison begins to hang out with her and her friends after she argued with the Prefects as well as to get back at Ja'mie.
• Emma, portrayed by Sharley White, is a part of Ja'mie's former best friend group. Even though Ja'mie no longer hangs out with them in this season, Madison soon joins the group to get revenge.
• Mel, played by Alice Stewart, like Emma is a part of Ja'mie's ex-friends group. Madison also befriends Mel to get back at Ja'mie.