They join previously announced performers Miley Cyrus and Imagine Dragons.
Additional acts and presenters will be announced in the coming weeks, the network said.
The prize presentation is to take place Nov. 24 at the NOKIA Theatre L.A. LIVE.
"Florida Georgia Line and One Direction have made an incredible impact over the past three years," Larry Klein, producer of the American Music Awards telecast, said in a statement Friday. "We are thrilled to have them make their AMA debut performances this year."