The third season of Degrassi Junior High premiered on November 7, 1988 with 16 episodes. It portrays the 1989-1990 school year.
- Neil Hope as Derek "Wheels" Wheeler, a troubled student struggling with the death of his adopted parents and contemplating running away from home, plays bass in the band Zit Remedy.
- Stefan Brogren as Archibald "Snake" Simpson, a tall, friendly student who discovers his older brother is gay, plays guitar in the band Zit Remedy.
- Anais Granofsky as Lucy Fernandez, a worldly, popular girl with neglectful parents who runs into problems when she starts dating older boys.
- Amanda Cook as Lorraine "L.D." Delacorte, an athletic tomboy and feminist.
- Angela Deiseach as Erica Farrell, a loud, goofy and boy crazy girl who has a love/hate relationship with her twin sister.
- Maureen Deiseach as Heather Farrell, a somewhat timid girl with strong morals who has a love/hate relationship with her twin sister.
- Amanda Stepto as Christine "Spike" Nelson, an easy-going, punk-rock girl who is dealing with being a new teen mom.
- Cathy Keenan as Liz O' Rourke, an opinionated, punk rock girl getting involved with political activism and animal rights.
- Bill Parrot as Shane McKay, an irresponsible party-boy and teen dad experimenting with drugs.
- Irene Courakos as Alexa Pappadopolos, a overly dramatic, boy-obsessed girl.
- Michael Carry as Simon Dexter, a cute student and Alexa's on-again, off-again boyfriend, famous from starring in a local commercial.
- Maureen McKay as Michelle Accette, a shy girl who pursues an interracial relationship (much to the protest of her racist parents), Alexa's close friend.
- Dayo Ade as B.L.T. Thomas, an athletic student who loves basketball and deals with racism, Michelle's boyfriend.
- Pat Mastroianni as Joey Jeremiah, a humorous and immature class clown who is known for slacking off, currently repeating grade 8, plays keyboard in the band Zit Remedy.
- Stacie Mistysyn as Caitlin Ryan, a human rights activist and aspiring journalist discovering the pains of first love.
- Sara Ballingall as Melanie Brodie, a gawky but open-minded girl who is making awkward first attempts at 'fitting in'.
- Rebecca Haines as Kathleen Mead, the school's gossipy vice-president who develops an eating disorder.
- Duncan Waugh as Arthur Kobalewscuy, an awkward outcast who has become recently wealthy due to his mother winning the lottery.
- Siluck Saysanasy as Yick Yu, a nerdy outcast who wants to fit in, struggling with his best friend's newfound wealth.
- Christopher Charlesworth as Scooter Webster, a geeky advanced placement student, picked on by the other students.
- Trevor Cummings as Bartholomew Bond, a smart, snobby loner, Scooter's best friend.
- Roger Montgomery as Mr. Garcia, the math teacher who also teaches extra classes on difficult subjects such as AIDS, generally teaches grade 9.
- Dan Woods as Daniel Raditch, the strict English teacher, generally teaches grade 8.
- Michelle Goodeve as Karen Avery, the history/geography teacher, generally teaches grade 7.
- Deborah Lobban as Doris Bell, the nosy school secretary.
- Susin Nielson as Louella Hawkins, the hard working school janitor and custodian.
- Steve Bedernjak as Clutch, a older, hard drinking, troublemaking student at Borden High. (Grade 11)
- Michael Blake as Paul, an older student at Borden High, Lucy's love interest. (Grade 11)
- Sara Holmes and Jacy Hunter as Amy Holmes and Alison Hunter, inseparable best friends, stuck up and snobby troublemakers. (Grade 9)
- Arlene Lott as Nancy Kramer, the know-it-all school president who keeps herself updated on everything. (Grade 9)
- Keith White as Tim O'Connor, a smart, bookish student, Nancy's best friend. (Grade 9)
- Andy Chambers as Luke Matthews, a troublemaking student involved in drugs. (Grade 8)
- Kyra Levy as Maya Goldberg, a Jewish girl in a wheelchair. (Grade 8)
- John Ioannou as Alex Yankou, the school's biggest nerd. (Grade 8)
- Danah-Jean Brown as Trish Skye, a quiet red-headed girl, active in many school activities. (Grade 8)
- Tammy Campbell as Trudi Owens, a punk rock student with a bright red streak in her hair. (Grade 8)
- Chrissa Erodotou as Diana Economopoulos, a boy-crazy girl with strict Greek parents. (Grade 8)
- Annabelle Waugh as Dorothy, Arthur's geeky cousin who develops a crush on Yick. (Grade 7)
- Kirsten Bourne as Tessa Campanelli, a hyperactive, immature girl. (Grade 7)
- Samanth Morrison as Emma Nelson, Spike and Shane's baby daughter.
Main article: Episode Guide
|Season #||Series #||Title||Original Airdate||Production Code|
|1||27||"Can't Live With 'Em, Part One"||November 7, 1988||301|
|2||28||"Can't Live With 'Em, Part Two"||November 7, 1988||302|
|3||29||"A Big Girl Now"||November 14, 1988||303|
|4||30||"Season's Greetings"||November 21, 1988||304|
|5||31||"Loves Me, Loves Me Not"||November 28, 1988||305|
|6||32||"He Ain't Heavy..."||December 1, 1988||306|
|7||33||"The Whole Truth"||December 12, 1988||307|
|8||34||"Star-Crossed"||January 16, 1988||308|
|9||35||"Food for Thought"||January 23, 1989||309|
|10||36||"Twenty Bucks"||January 30, 1989||310|
|11||37||"Taking Off Part One"||February 6, 1989||311|
|12||38||"Taking Off, Part Two"||February 6, 1989||312|
|13||39||"Making Whoopee"||February 13, 1989||313|
|14||40||"Black & White"||February 20, 1989||314|
|15||41||"Pa-arty!"||February 27, 1989||315|
|16||42||"Bye-Bye, Junior High"||March 6, 1989||316|