The C'est La Vie singers have put aside past differences to take part in the programme.
Also taking part will be Michelle Heaton's old band Liberty X alongside Atomic Kitten, 5ive, 911 and Honeyz.
Singer Lindsay Armaou
broke the news of the Irish group's comeback on her Twitter page after she posted the first image of the group together in over a decade.
"First B*witched photo after 12 years... Weird!" she wrote.
B*Witched first found chart success in the late 1990s, clocking up hits with songs like Blame It On The Weatherman.