The singer was a fixture on the reality Tv show for the first two series but she has announced she is walking away from the hot seat to concentrate on her music career.
In a note to fans on her website, she writes, "All good things come to an end. I have absolutely loved being a coach on The Voice of Ireland. What an amazing show!
"The first two seasons were quite the roller coaster ride - we took it from concept stage to the number one television program in the country and I could not be more proud."
She adds, "I am very excited to be releasing my new album The Same Sun, there are a lot of promotional activities scheduled and I am embarking on a world tour very soon, so unfortunately, I cannot be with you all this season - I wish everyone involved good luck and I look forward to seeing you all again in the future."
British R&B star Jamelia has also stepped down as a judge on the show after winning the most recent season with singer Keith Hanley, and it is still not clear if former Westlife star Kian Egan will be returning to the show for season three.
The latest The Voice news comes just a day after it was announced will.i.am would be returning as a judge to Britain's The Voice. The Black Eyed Peas reportedly turned down a spot on American Idol to rejoin Tom Jones on the show.
Meanwhile, Cee Lo Green and Christina Aguilera will be returning as judges on America's version of the talent show after taking a season off. Their spots were filled by Usher and Shakira earlier this year (13).