Sydney White (Amanda Bynes) is the daughter of a plumber, and has grown up among construction workers ever since her mother died when she was nine. Sydney earns a scholarship for college and hopes to follow the legacy of her mother and enter the Kappa Phi Nu sorority. Shortly after arriving at Southern Atlantic University, Sydney clashes with the sorority president Rachel Witchburn (Sara Paxton), after Rachel sees Sydney talking to her ex-boyfriend (although according to Rachel and those who speak on her behalf, he is her on-off boyfriend) Tyler Prince. Rachel tries to deny Sydney's bid for membership in the sorority, but cannot because Sydney's mother was a member. Despite Rachel's hazing, Sydney successfully meets all of the requirements during her time as a Kappa pledge.

Rachel schemes to keep Sydney out of the sorority and uses her presidential authority to declare Sydney unfit to be a Kappa. Humiliated, Sydney immediately leaves the Kappa house. With no place to go, Sydney is taken in by seven outcast students who live in “The Vortex” (which is called The Vortex because “it sucks in losers”), a house on Greek Row for people who don't belong. In the house, she befriends all the guys (“the dorks”), especially Lenny, (Jack Carpenter) who falls for Dinky Hodgekiss (Crystal Hunt), one of Sydney's popular friends.

The Vortex, however, is badly in need of repairs, and the Greeks will not pay for it. Rachel tries to get it condemned so she can build a Greek Centre in its place. An angry Sydney convinces one of her housemates, Terrance, to run for Student Body President on the “Freedom to the 7th Power” ticket in order to take back what the Greeks have had for so long. But he is disqualified because he graduated 7 years before but did not leave the Vortex and the “Dorks” are kicked out of the Vortex by the Health Department. Sydney then runs for president herself.

Meanwhile, Sydney's Hot or Not ranking on the school's website gradually rises to overtake Rachel's #1 position, which infuriates her. It is part of Rachel's daily routine to consult her computer (“mirror mirror on the wall”) to see “who is the fairest of them all.” Enraged, Rachel visits a hacker who remotely infects Sydney's computer (a “poisoned Apple”), which erases an important paper due the next day. Sydney studies all night at the library, and fails to awake in time for the presidential debate. Tyler finds her, tells her she must wake up, and kisses her, which, “breaks the spell”. Together, they rush to the debate and Sydney gives a triumphant speech. Many members of various “dorky” groups on campus arrive to show their support. An angry Rachel is stripped of her presidency by her sorority sisters.

In the end, Sydney's dad and his colleagues repair the Vortex and Sydney White gets her prince.