Swift picked up the top prize of Artist of the Year and also won the statuettes for Favorite Female Country Artist and Favorite Country Album for "Red."
Justin Timberlake was named Favorite Male Pop/Rock Artist and Favorite Soul/R&B Artist. He also took home the award for Favorite Soul/R&B Album for "The 20/20 Experience."
Rihanna earned the honor for Favorite Female Soul/R&B Artist, as well as the inaugural AMA Icon Award.
One Direction won the title of Favorite Pop/Rock Band, Duo or Group, and its record, "Take Me Home," was named Favorite Pop/Rock Album.
Ariana Grande was crowned New Artist of the Year and "Cruise" by Florida Georgia Line, featuring Nelly, was declared the Single of the Year.
The awards ceremony at the Nokia Theatre L.A. Live was presided over by recording star Pitbull.