Cheryl Cole - who was given her big break on TV talent show Popstars: The Rivals - will tell the X Factor hopefuls she can sympathise because she has been in their position.
The Girls Aloud star says: "I've been there and I have been here so I know how you are all feeling, I am just excited to see what you have got. [I] think it's going to be amazing and I wish you the best of luck from the bottom of my heart."
Other guest mentors include Tinie Tempah, who teams up with Tulisa Contostavlos, Ne-Yo who accompanies Nicole Scherzinger and Sharon Osbourne who is the sidekick to Louis Walsh.
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At least two are dead with over a dozen injured after an attack on a teen event. Here is what we know so far.
Aspiring basketball player Stefan Strawder was gunned down as he left a teen night at Club Blu.
The suspect, armed with a gun, was caught on CCTV wearing the fancy dress mask, with a red cap on top.