Cheryl Cole will mentor the female category
The 12 final X Factor acts, who will perform live on next Saturday's ITV1 show, have been selected by the judges.
Simon Cowell, who is mentoring the male acts, chose Eoghan Quigg, Austin Drage and Scott Bruton.
Alexandra Burke, who entered the show in 2005, Laura White and Diana Vickers are the female acts who will appear.
Ex-prisoner Rachel Hylton, Daniel Evans and Ruth Lorenzo were selected in the over-25s category and Girl Band, JLS and Bad Lashes are in the band section.
Last year's winner Jackson will be the first star performer on the show, singing his new single Don't Call This Love.
In September it was also confirmed US pop star Britney Spears would perform.
Sunday night's show pulled in an average of 9.5 million viewers.