"I'm extremely excited to be joining the panel of judges for 'The Sing-Off' this fall!" Bareilles said in a statement. "A cappella music is very near and dear to my heart, and I have been a huge fan of the show from the beginning. I love the opportunity to be a part of something that celebrates a genre of music that I just adore and believe in. I can't wait for it to start."

The Grammy nominee will replace Nicole Scherzinger on the judging panel. Scherzinger is moving over to Fox's 'The X Factor.' Originally tapped to host the new Simon Cowell reality series, Scherzinger moved over to the judging panel after British pop star Cheryl Cole got the axe.

Viewers will remember Bareilles as a guest performer during last season's 'Sing Off' competition.

"I love the fact that on this show, the judges are each so rooted in the world they preside over," Paul Telegdy, executive vice president of alternative programming at NBC, said in a statement. "Simply put, they can do what the contestants are doing and that means a lot. Sara will bring a sublime technical knowledge and huge appreciation for 'The Sing Off ' -- she's a fan and we're thrilled she's coming on board."