Swift took kudos for female performer, live act and best look, which is a new category. She also performed “We Are Never Ever Getting Back Together” in the show’s finale.
Bieber was voted top in the world stage, pop and male categories.
Carly Rae Jepsen won in the Push and song categories for “Call Me Maybe.” British boy band One Direction earned best new act and the award for having the biggest fan following.
Korean pop star Psy, known best for “Gangnam Style,” took home the award for video. He performed the “Gangnam Style” dance with a large troupe of lookalikes.
Chinese artist Han Geng nabbed the worldwide act honor.
The late Whitney Houston was named Global Icon, honored for her impact on the pop music world.
The event, which had a circus wonderland theme, was presented by Heidi Klum and exec produced by Bruce Gillmer and Richard Godfrey.
Among the acts performing were Rita Ora with “R.I.P.,” fun. with “We Are Young,” Alicia Keys with “Girl on Fire,” Pitbull with “Don’t Stop the Party,” The Killers with “Runaways,” Muse with “Madness” and No Doubt with “Looking Hot.”
Presenters included Lana Del Rey, who won the award for alternative act, Kim Kardashian and Nick, Kevin and Joe Jonas. Other guests included Kanye West, Gwen Stefani and David Hasselhoff.
MTV said the awards attracted 184 million votes online and on mobile devices.