The event, co-hosted by Jessica Alba and Jeremy Piven, celebrated the superstars of the social networking world, and Bieber beat out competition from top Tweeters Katy Perry, Psy and Rihanna to claim the Most Popular Music Solo Artist prize.
Meanwhile, Spring Breakers star Gomez was named Most Popular Actor, ahead of male rivals Jackie Chan, Justin Timberlake and Will Smith.
One Direction also took home a prize for Most Popular Music Group. Accepting the award via videolink, Harry Styles said, "‘We wanna say a massive thank you for the Best Social Star Group of the year award. Thank you for our Starcount award, and we will see you soon!”
Other winners included comedienne Ellen DeGeneres, who won the prize for Most Popular TV Show, while Twilight was honoured with the Most Popular Film accolade.
Rockers Aerosmith kicked off the ceremony with a live performance, followed by sets by Carly Rae Jepsen and South Korean pop sensation Psy.