The pop star, 22, and beau Conor Kennedy, 18, are over, sources confirm to PEOPLE.
The pair, who enjoyed a whirlwind summer romance frolicking through Hyannis Port, Mass., showing several public displays of affection, split a while ago.
"His friends have said it's over," says a source at his school, the Deerfield Academy, adding, "I have the feeling she ended it."
It's a bummer since Swift even got the stamp of approval from Conor's grandma, Ethel Kennedy, who called the starlet, "spectacular."
In August, a source told PEOPLE Swift was "swept off her feet" by her then-boyfriend.
But Swift's busy schedule could have made things difficult. She's currently promoting her new album, Red, performing at the Country Music Awards Thursday, will co-host the Grammy nomination concert, and just announced a 2013 tour.
For the lowdown on her past breakup songs, pick up the new issue of PEOPLE, on newsstands Friday