The reigning champ from last year's series will return to the show a year to the date that she made her live debut in 2015.
The news follows Louisa revealed her brand new single called So Good which is available to download and stream now.
Louisa tweeted: "Buzzing to be back on @TheXFactor next sunday with my new track! ⚡️#Sogood"
She added in a video message on the official X Factor website: "I'm so excited to be coming back home to perform my new single So Good on The X Factor."
While Louisa's new single is out now, she's "breaking the mould" and NOT releasing an album this year.
In a first for an X Factor winner, Louisa will be delaying her debut record meaning it will be out more than a year since she won the show.
Speaking about her 2017 album, Louisa explained to the Daily Mirror newspaper: "I am happy it’s worked out this way, I did want a song out before X Factor came around again, but I didn't want an album out in November.
"I wanted to break the mould.
"I just want to make it as perfect as it can be. Like, 'Here you go world, this is my life on a CD'."
Back to Sunday night, and Louisa will share the stage with Bruno Mars who will perform his new song.
The X Factor is back Sunday night at 8PM on ITV with the performances plus the latest results where another act will leave.
Sunday evening will also see the Jukebox wheeled out again to decide next weekend's theme.