It's Judges' Houses!
Each act is fighting for their place in the Live Shows, and each Mentor can only put three acts through, so the pressure is on!
Louis is joined in Ibiza by Fleur East and Alesha Dixon, while Simon has Spice Girls Mel B and Emma Bunton by his side.
Here's what you can expect from tonight's show!
Nicole Scherzinger's Boys got to jet off to the beautiful South of France to visit Nicole in Nice...and they also got to perform for superstar DJ Calvin Harris!
The Boys category includes James Hughes, Freddy Parker, Niall Sexton, Christian Burrows, Nate Simpson, Matt Terry and Wild Card act Ryan Lawrie!
After claiming victory in the Six Chair Challenge, The Girls jetted off to Simon Cowell's house in Malibu for the next leg of the competition!
See how Soheila Clifford, Kayleigh Marie Morgan, Caitlyn Vanbeck, Gifty Louise, Emily Middlemas, Olivia Garcia and Wild Card Samantha Lavery enjoyed their time Stateside!
How much attention were you paying to The X Factor's Six Chair Challenge last weekend? Now's the time to find out with our Six Chair Challenge quiz!
The Girls, the Boys, the Overs and the Groups fought it out for their place at Judges' Houses, and there's a few Wild Cards in there, too!