The announcement was made by Orly Adelson, president of dick clark productions.
This will mark Rihanna's fourth time performing on the AMAs. She joins a lineup of previously announced acts including Diddy-Dirty Money, Ne-Yo, Bon Jovi, P!nk, Christina Aguilera, Justin Bieber, Katy Perry, Ke$ha and Usher.
Rihanna is nominated for an AMA in the Soul/Rhythm & Blues category for Favorite Female Artist.
The prize presentation is to be broadcast live from the NOKIA Theatre L.A. LIVE Nov. 21 on ABC.
"We could not be more excited to officially announce one of pop music's biggest stars to open the celebration at the AMAs. Be sure to tune in so you don't miss this surely memorable moment," AMA producer Larry Klein said in a statement.