Bareilles will appear as a judge alongside Ben Folds and Shawn Stockman (of Boyz II Men) as The Sing-Off morphs into a weekly, two-hour series this fall (having previously aired in 2009 and 2010 as holiday events). Nick Lachey continues as host.
"I love the fact that on this show, the judges are each so rooted in the world they preside over," says Paul Telegdy, NBC's executive vice president of alternative programming. "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."
The singer replaces Nicole Scherzinger, who exited the show in order to take a job on Fox's The X-Factor. Scherzinger was originally set to co-host The X-Factor, but later replaced Cheryl Cole as a judge alongside Simon Cowell.
The Sing-Off pits a capella groups against each other as they compete for a prize (such as cash and a Sony Music recording contract). Bareilles comes to the show with plenty of cred: While studying at UCLA, the artist was a member of the a capella group Awaken A Cappella.
"A cappella music is very near and dear to my heart, and I have been a huge fan of the show from the beginning," Bareilles says. "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."
Bareilles is no stranger to The Sing-Off, having performed on the show's Season Two finale last December.
A three-time Grammy nominee, Bareilles is signed to Sony Music's Epic label (keeping things in the family, as Sony Pictures TV produces The Sing-Off). Her most recent studio album, Kaleidoscope Heart, included the hit song "King of Anything."
The Sing-Off's third season debuts Monday, Sept. 19, at 8 p.m. on NBC.