The singer and Heart FM DJ will replace Ruthie Henshall on the panel, joining show regulars Jason Gardiner, Nicky Slater, Karen Barber and Robin Cousins.
"I can't wait. I've been a huge fan since the show began," she told The Sun.
The 'Wannabe' popstar appeared on the 2006 series of Strictly Come Dancing, finishing in third place.
Dancing On Ice returns to ITV in January. Ex-soap star Danny Young, Hollyoaks actor Kieron Richardson, Boyzone's Mikey Graham and Heather Mills are all tipped to be taking part.