Rachel appeared on the sixth series of the ITV talent contest in 2009, becoming the fourth act to be eliminated from the live shows.
She is fondly remembered for the way voiceover man Peter Dickson bellowed her name, with Dickson having named her as his all-time favourite contestant to introduce.
Now, just over six years later, the 24-year-old has landed her first major TV acting role on the Channel 4 soap.
She will play the real Lisa Loveday, daughter of Louis and Simone Loveday, who was abducted from her school as a child.
Rachel's first storyline will see her character claim her family back from Sonia Albright, an impostor who has assumed Lisa's identity.
"I am so excited to have joined Hollyoaks and be part of the Loveday family, who are brilliant actors and already feel like an extension of my own family!" she said.
"It is quite a pressure to be coming in as the real Lisa Loveday as she is such an anticipated arrival in Hollyoaks village."
Rachel has already begun filming on the Hollyoaks set, and can be seen briefly in the show's new Spring 2016 trailer (embedded below). Her first scenes are slated to air in April.
Following her time on The X Factor, Rachel released her own dance music EP and recorded music videos for her songs 'Follow The DJ' and 'Club Lights'.
More recently she has tried her hand at stage acting, with roles in musicals Thriller Live and Jesus Christ Superstar.