The X Factor finalists will release a cover of Rose Royce's 1978 hit Wishing On A Star in aid of a children's charity.
All 16 acts will record the song in London this week ahead of its release next month in support of ACT and Children's Hospices UK.
X Factor supremo Simon Cowell said he had worked closely with the charity, adding that having seen "the amazing work they do for kids and their families who need help and support, I am thrilled that the X Factor charity single this year will benefit this charity".
Finalist Frankie Cocozza said it was "a brilliant thing to be doing for a brilliant charity".
Kitty Brucknell said: "It's incredible to be able to give something back and hopefully help a lot of people."
The song, which originally got to number three in the charts, will be released as a download on November 19 and then fully the day after.
Barbara Gelb from the charity said she was "delighted" at the news.
She said: "The money raised from this single gives us the opportunity to improve the lives of these children and families - and crucially raise awareness of the valuable support they need, wherever they live and for as long as they need it.
"Every single bought, either on line or through the high street, will make such a difference."
It is the fourth charity release from the X Factor, following last year's cover of David Bowie's Heroes for Help For Heroes, 2009's cover of Michael Jackson's You Are Not Alone which supported Great Ormond Street Children's Hospital and 2008's Hero which raised more than £1.3 million, also for Help For Heroes.