Panelists Gary Barlow, Kelly Rowland, Tulisa Contostavlos and Louis Walsh confirmed the lineup on tonight's final Boot Camp episode.
Advancing in the boys category are 18-year-old lothario Frankie Cocozza, Joe Cox, Luke Lucas, returning contestant John Wilding, barber Marcus Collins, Max Vickers, James Michael and Craig Colton.
The successful Overs were named as Samantha Brookes, Joseph Gilligan, Goldie Cheung, Johnny Robinson, ex-Fame Academy contestant Carolynne Poole, Jonjo Kerr, Terry Winstanley and controversial hopeful Kitty Brucknell.
Meanwhile, Amelia Lily, Misha Bryan, Holly Repton, Sian Phillips, Janet Devlin, Jade Richards, Sophie Habibis and Melanie McCabe made it to the next round in the Girls category.
When it came to the groups, the judges shook things up by forming a new band called Rhythmix out of soloists Jesy Nelson, Perrie Edwards, Jade Thirwell and Leigh-Anne Pinnock to put through with The Lovettes, Girl V Boy, The Keys, Nu Vibe, 2 Shoes, The Risk and Estrella.
The X Factor judges also discovered in tonight's edition which category they will be mentoring for the rest of the show.
Contestants will be seen travelling to Judges' Houses on next Saturday's episode of The X Factor, which airs at 7.30pm on ITV1.
> X Factor John Wilding interview: 'I thought I'd blown my chance'
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Click along Digital Spy's gallery below for pictures of all 32 remaining acts, who will be fighting it out at Judges' Houses.