The 'EastEnders' actress is the first female celebrity contestant confirmed to be taking part on the BBC dance show, after Radio 2 presenter Jeremy Vine and TV chef Ainsley Harriott were announced earlier this week.
Chris Evans confirmed her involvement during his Radio Breakfast Show on Wednesday morning.
Kellie admitted she has already started getting fit ahead of her taking to the 'Strictly' dancefloor.
"I've been working out to get fit and strong," she said. "I'm at an age where if I sit too long I have to unfold myself!"
She added: “There are two main reasons I want to take part in this year’s Strictly Come Dancing. The first is that as I will be turning 40 next year, I think it is the perfect time for a new, exciting challenge.
"The second reason is because if I said ‘no’ Linda Carter would never forgive me!”
Kellie is best known for her role as Queen Vic landlady, Linda Carter, in 'EastEnders' who she has played since 2013.
Earlier this year, Kellie won both ‘Best Actress’ and ‘Best Dramatic Performance’ at The British Soap Awards 2015 for her performance in the BBC soap.