Katie was a finalist in the 2010 series of X Factor where she was mentored by Cheryl, and has been VERY vocal ever since about not getting along with her.
“If you ask me, she is as fake as s**t," Katie said in an interview last year. "“I just think there's no substance to her. She can be very abrupt and rude. I don't think she's a very nice human.
“My advice to anyone who's going to be on the show would be to f***ing beg to get someone else as mentor. I told [Rita Ora] I hung out with Simon and Louis Walsh and Cheryl sat with her Benson & Hedges in her dressing room staring at her diamonds.”
Now Katie is set to join the Celebrity Big Brother house and could reveal all about what went on behind the scenes at The X Factor.
A source told The Sun newspaper ahead of tonight's live launch show: “Cheryl and Simon are definitely going to be worried about Katie going into CBB.
“Katie felt massively mistreated on the X Factor and they know she knows things they wouldn’t want coming out of the woodwork.”
The source added: "Katie is fiery and speaks her mind.”
Katie is one of 15 celebs expected to enter tonight, alongside another X Factor act from 2010, Chloe Khan.
Then known as Chloe Mafia, she was rejected by the judges at bootcamp but has gone on to become a model in the US, even gracing the cover of Playboy.
CBB begins at 9PM on Channel 5 tonight.