Jewel will join country singer, songwriter and producer and John Rich, who was previously announced as a sixth-season judge and mentor.
"I am so excited to be a part of Nashville Star, to help mentor young artists and cultivate their singing, songwriting and playing and to encourage and continue that tradition," said Jewel.
Hosted by former Dancing with the Stars fourth-season celebrity participant Billy Ray Cyrus, Nashville Star's sixth season will premiere Monday, June 9 at 9:30PM ET/PT. The winner will receive a recording contract and the opportunity to perform at the 2008 Summer Olympic Games in Beijing, which will commence August 8 and be broadcast on NBC.
NBC plucked Nashville Star from its sister network USA -- which aired the first five seasons of the reality competition series -- in January. At the time, NBC stated "a new host and judges" for the sixth season would be announced at a later date -- and when Cyrus was tapped to helm the show's sixth installment, it looked like Jewel's involvement in the show could be over.
However Nashville Star executive producer Howard T. Owens stated that by having Jewel as a sixth-season judge and mentor, contestants will be "learning from an artist that personifies American music."
"She is an amazing singer/songwriter, musician and performer that will give great insight to both the contestants and television viewers and that again elevates the competition with her participation in the show this season," said Owens.
Jewel's first country album -- " Perfectly Clear" -- is scheduled to be released June 3, less than a week before Nashville Star's sixth-season debut. The album's first single, "Stronger Woman," currently sits at No. 14 -- its peak position -- on the Billboard Hot Country Songs singles chart.