The contestants' version of 'You Are Not Alone' will be performed for the first time during the results show on Sunday November 15, before going on sale the following day.
Sick children from Great Ormond Street Hospital will be in the audience to watch the rendition.
In 2008, the X Factor finalists generated over £1 million for Help for Heroes with their cover of Mariah Carey's 'Hero'.
Simon Cowell said: "This year we chose to work with Great Ormond Street to help raise funds and awareness for their incredible work.
"I'm very proud of the single and I really hope it raises an enormous amount of money for people who really need our help."
Louis Walsh added: "Great Ormond Street Hospital does some incredible work and I implore everyone to go out and buy the single to help raise money for such a worthy cause."
Dannii Minogue stated: "I have been aware of the amazing work Great Ormond Street does for a long time, coming into contact with many families who have benefited from their tireless care and attention.
"Their work is incredible and I'm so pleased that we are able to offer them support with this single."
Dr Jane Collins, chief executive at Great Ormond Street Hospital, commented: "We really hope that the public will buy this recording so we can raise as much money as possible to allow us to continue to help sick children from across the UK get better."
Meanwhile, 14-year-old Jade Rowles said: "I think it's brilliant that The X Factor is supporting Great Ormond Street Hospital because last year I got to meet Alex [Burke] just after I'd had my lung transplant.
"The visit from her really cheered me up and she even invited me to the X Factor live tour - one of the best nights of my life. If you buy this record you'll be helping lots of other kids like me."
The X Factor continues tonight at 8pm on ITV1.