The Wizards Of Waverly Place star was selected in the categories for best TV actress, female hottie and music group with her band The Scene.
CLICK ON PHOTO FOR GALLERY OF GUESTS
Their disc Who Says won the trophy for best single.
Meanwhile, Love You Like A Love Song, which they performed at the ceremony, received the prize for best love song.
"This is for all of you guys," 19-year-old Selena told the screaming crowd. "This isn't mine."
Justin, Selena's 17-year-old boyfriend, picked up four surfboard-shaped trophies.
He took home awards for best male music artist, male hottie, twitter user and 'TV villain' for his CSI guest starring role.
Other winners included Glee, The Vampire Diaries, The Twilight Saga, Harry Potter And The Deathly Hallows, Robert Pattinson and Taylor Swift.
"I feel like it's been a long time since I was a teenager, like, two years," Taylor joked.
Like Selena, the 21-year-old singer scooped five awards including choice female music artist.
She was also honoured for her contributions to entertainment with the 'Ultimate Choice Award', the show's version of a lifetime achievement award.
Cameron Diaz was named 'Choice movie comedy actress' for her role in Bad Teacher.
Fans were thrilled to see Sean Kingston making his first live TV appearance since serious jet-ski accident in May.
And Demi Lovato – who entered a treatment facility last November to deal with "emotional and physical issues" – accepted two awards.
"You guys are what got me through this last year," she told the audience.
And Ashton Kutcher picked up 'Choice romantic comedy movie actor' for No Strings Attached.
Harry Potter's final two instalments won awards for best sci-fi/fantasy movie and 'liplock'.
The series baddie Tom Felton was singled out as the top villain, while both Emma Watson and Daniel Radcliffe won in the summer movie star category.
Also in attendance was the fashionable Kardashian clan. Kim looked especially stunning in a monochrome ensemble – just weeks before her wedding to basketball star Kris Humphries.