The pop star posted a pic on Twitter of herself swathed in sequins – and showing off her toned figure in a cat suit with cut out side sections.
Kimberley will join her co-stars from the dancing reality TV show in a special launch show on BBC One this Saturday, during which their dance partners will be revealed.
But Kimberley seemed to have let the cat out of the bag early by adding a second photo of her with the show's pro Anton du Beke.
Other stars taking part in the programme include Olympians Victoria Pendleton and Louis Smith.
Gold-medal winning cyclist Victoria, 31, who retired from the sport after the London Games, had made no secret of her desire to take part in the BBC One ballroom dancing contest.
Victoria's agent confirmed her involvement in the show on Twitter.
The message said: "@v_pendleton IS doing Strictly - pretty exciting and no doubt she'll work at it to become a very good dancer. That's what athletes do."
Gymnast Louis, who won a silver medal in the pommel horse event and has hinted that he will not compete in Rio 2016, has already appeared on a previous series of The X Factor.
Fellow sportsman Michael Vaughan is expected to take to the dancefloor alongside the 23-year-old gymnast. The 37-year-old former England captain would follow in the footsteps of cricketers Darren Gough and Mark Ramprakash, who have previously won Strictly.
Other famous faces confirmed include Westlife's Nicky Byrne, Daybreak presenter Richard Arnold and actress Dani Harmer.
Former children's TV host Johnny Ball joins them too - the oldest competitor at the age of 74 - alongside model Jerry Hall and actor Sid Owen, best known for appearing as Ricky Butcher in EastEnders.
They are set to be joined by presenter Fern Britton, who participated in the Strictly Christmas special in 2010 and former Emmerdale actress Lisa Riley. James Bond actor Colin Salmon and actress and singer Denise Van Outen are set to complete the line-up.
All of the contestants hid behind Sir Bruce Forsyth masks when they arrived at a south London dance studio for rehearsals at the weekend.