Mum-of-one Frankie, 25, made the big announcement during an appearance on BBC Breakfast with her bandmates on Wednesday morning.
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Frankie Bridge is the first confirmed celebrity taking part in Strictly
"I'm such a huge fan of Strictly!," the singer said. "I've always wanted to be a part of the show – it looks so much fun and the costumes are just gorgeous.
"Like so many little girls, I used to take dance lessons when I was in primary school and I really love dancing, but this is going to be so different from anything I have done with The Saturdays. I just can't wait to get started!"
Frankie Bridge on stage with her Saturdays bandmates
As one fifth of a chart-topping girl group, Frankie is used to being in the spotlight – and the dancing skills she's already picked up from being on stage will no doubt stand her in good stead once the competition gets underway.