Ryan received a standing ovation for her audition with her rendition of Queen's hit song Somebody To Love.
The shock decision to bring the quizmaster back for the live shows was announced on Twitter.
The X Factor celebrity announced: "The Judges have decided that there is one person who still deserves a coveted spot in the #XFactorCelebrity Live shows. We're pleased to announce @jenlion will be joining,".
The news took Ryan by surprise, and she took to Twitter to thank fans for their support.
"I'm thrilled to have been thrown this lifeline, I won't let you down. See you at the lives on Saturday!" she said.
I was DEVASTATED that the judges didn't put me through, but the tidal wave of love & support I got from you all was incredibly uplifting, I am SO grateful. I'm thrilled to have been thrown this lifeline, I won't let you down. See you at the Lives on Saturday! #XFactorCelebritypic.twitter.com/mV0Aoxpp0M
The X Factor UK: Celebrity is judged by Cowell, Nicole Scherzinger, and Louis Walsh, and contestants are competing for a chance to win a record deal with Simon Cowell's label.