The Bootylicious star joins a rather exclusive club of artists, as former recipients include Michael Jackson, Rod Stewart, Led Zeppelin, the Bee Gees and Aerosmith.
For the first time in AMA's 35-year history, winners were selected by the public via online voting - the show's broadcaster ABC reported that around 1.2 million people voted.
Nominees were selected based on national sales and radio play, and included Brits Natasha Bedingfield and James Blunt, who both attended the glitzy ceremony held at the brand new Nokia Theatre in downtown Los Angeles.
However, it was strictly the Americans who won big. Justin Timberlake was named Pop/Rock's Favourite Male Artist and his album FutureSex/LoveSounds won in the Soul/Rhythm & Blues category. In a recorded acceptance speech from Australia, Justin said the win was "awesome".
Singer Fergie, who also performed for the star-studded audience, was named Pop/Rock's Favourite Female Artist.
Other winners included Nickelback and Rihanna. Disney's teen sensation High School Musical 2 picked up Favourite Soundtrack Album.
Source: pa.press.net