The former Playboy model and the 'Look Who's Talking' actress will battle it out on the dancefloor against the likes of former boxing champion Sugar Ray Leonard, NFL star Hines Ward and model Petra Nemcova.
Speaking about taking part in the show, Kirstie - whose weight has fluctuated over the years - said: "We're going to try to not fall on our butts the first week out. That's what I'm going for."
Former Disney actress Chelsea Kane will also compete and admits the nerves are already starting to show.
She said: "I don't know how I'm going to react to the judges when there's a camera on my face and I'm trying to smile through it. Hopefully, I won't ruin my make-up."
The celebrities - whose professional partners have not yet been announced - have just three weeks to prepare before the show kicks off on March 21.