When Sabrina's bitter math teacher Mr. Rothwell singles her out for unfair treatment, and her aunts are unable to make him see reason, the witch trio decide it's time to teach him a few of their own spellbinding lessons. When he's hauled into traffic court, they replace the human judge with a magical substitute who's been hibernating in a deep freeze "to prevent media bias." Meanwhile, Salem panics when his ex-girlfriend decides to pay him a surprise visit especially since she has no idea that he has been turned into a cat.
After spending the weekend at Jenny's, under the advice of her aunts, Sabrina reluctantly invites Jenny to her house. However, when Jenny enters the linen closet, she ends up in the Other Realm, at the mercy of Drell.
A stressed-out Sabrina gets a monstrous wart, which only worsens her foul mood. And despite everyone's efforts to cheer her, she seeks solace and solitude in an alternate world inside her mirror, where she becomes trapped in her own bad mood. To Jenny for ignoring her, to Harvey for ridiculing his use of a puppet spider monkey to get them through a school assignment she flubbed, and to Libby for turning her into a goat.
When Sabrina is disappointed that her aunts won't let her stay out late to see the famous rock band Violent Femmes, Hilda and Zelda decide to transform themselves into teenage chaperones as a compromise. But they're the ones causing the trouble when "Hillary" clashes with a security guard and a high-school boy falls for "Zellery." After proving that even teenage aunts can be embarrassing, they apologize by giving Sabrina her very first flying lesson -- aboard a vacuum cleaner.
Sabrina and her aunts take a trip to Mars, but Sabrina is reluctant to leave Harvey. She agrees to call him at a specified time, but when her attractive ski instructor takes a shine to her, she soon forgets about the mortal world.
As Sabrina and Harvey grow closer, her aunts reveal that when a witch kisses a mortal for the first time, the mortal turns into a frog. Unable to stop herself, however, Sabrina kisses Harvey, and must find a way to change him back.
Hoping to encourage more students to join the Adopt-A-Grandparent program, Sabrina finds a mischievous way to get trend-setting Libby to participate: she impersonates her, necessitating quick Superman-style telephone booth transformation whenever the real Libby turns up. But Sabrina's well-meant scheme goes wrong when Libby bonds with Sabrina's adopted grandmother Nana, who claims to know most of Hollywood's young hunks personally. Meanwhile, Zelda can't decide whether to continue dating a man who is centuries younger than she is; and Hilda and Salem eat too much of a...
Sabrina has blown her allowance, and Salem has maxed out his credit card over the phone, so they decide to enter a cat show to earn the prize money, but soon find themselves wrapped up in a blackmail scheme to force the judge to throw the competition, and, to avoid being caught, Sabrina has to transform herself into a contestant. Meanwhile, Hilda and Zelda seek out a magical perfume that will make Zelda repulsive to their love-sick mailman Dirk, and Hilda gets shrunk as a punishment for taking free samples in the magical "Full Moon" shop.
Preparing for her father's monthly visit, Sabrina anticipates the teenage trauma of introducing her father to her boyfriend (actually, Edward and Harvey do reasonably well), but isn't prepared for the teenage trauma of meeting your divorced father's new girlfriend, an attractive supernatural lawyer named Gail. Initially hostile, Sabrina is persuaded by her aunts to see reason and tries to make amends by asking whether Edward and Gail plan to get married. When they simultaneously answer "Yes" (Gail) and "No" (Edward), Gail furiously dives into Sabrina's magic book.
Sabrina, bored with her life, opens a magical can of worms which instantly transforms Sabrina's life into a dramatic soap opera. However, things don't go exactly as the teen witch originally planned, especially when she gets accused of being a thief.
Sabrina hits a really bad day: disregarding her aunts' warning, she buys a "tomorrow" ball from a supernatural traveling salesman, and believes its prediction that she will get an "A-" on her science project. Unfortunately, Mr. Pool doesn't share that estimation of her work, and gives her a C- and a chance to redo the project overnight. Instead, Sabrina tries to sneak out of the house aboard her trusty vacuum cleaner to attend a "Smashing Pumpkins" concert, but gets pulled over by a flying motorcycle cop and cited for flying over the town "with a full bag and bad dust...
Sabrina's fears become reality when she takes part in a re-creation of the Salem witch trials and is accused of sorcery while defending Jenny's honor. Libby made up a bunch of lies, just to get rid of Sabrina and Jenny, accusing them of practice witchcraft. At the end, all teachers realizes that she was lying, and Sabrina casted a spell on her as a revenge.
When Sabrina can't find her homework, she follows Salem's advice to consult a professional magic finder, but when troll Roland appears and quickly uncovers her missing notebook, he demands her hand in marriage as payment. Following him home to attempt reason she is trapped in his castle and can only be rescued by the prince she loves: Harvey. Has the moment come when he will learn the truth about Sabrina's unusual family?
Sabrina finds out that her vice-principal Mr Kraft has a crush on Hilda and sets the two up on a date. But Hilda can't stand him, so Sabrina turns her into a dummy and follows them on the date. Thanks to Hilda, Zelda must do community service in the Other Realm
Harvey tells Sabrina his parents want him to start dating other girls. Sabrina's aunts agree and set her up with a witch called Dante. They click and then go on a double date with Harvey and his date Jean. But Dante has a problem with not using magic in the mortal realm. Zelda uses the same dating service and has trouble finding a date, as does Valerie. Meanwhile, Hilda has a dose of 'Pun-Itis' which causes puns in her sentences to come true.
Sabrina decides to babysit her bratty cousin Amanda, who becomes bored and transforms Sabrina into a doll. Sabrina meets three other human-turned-dolls in Amanda's toy box and they plan to escape. Meanwhile, Hilda and Zelda try to spend time separately at a spa in the Other Realm.
Sabrina can't understand boys and when she senses something between Harvey and Valerie, she turns herself into a boy but ends up dating Libby. Hilda also transforms into a man to try and get rid of Mr Kraft.