Other contestants include Martin Kemp, Bill Turnbull, Aisling Bea and Ella Eyre.
American actress Teri Hatcher, comedian Alan Carr and leader of the Scottish Conservatives Ruth Davidson are among the stars taking part in The Great Celebrity Bake Off.
The special edition of Bake Off in aid of C4’s charity TV drive Stand Up To Cancer will see judges Paul Hollywood and Prue Leith return alongside presenters Noel Fielding and Sandi Toksvig.
Along with former Desperate Housewives star Terri, British comic Alan and politician Ruth, 17 other famous faces will also tackle tricky challenges in the baking tent.
The other confirmed star contestants include comedians Tim Minchin, Aisling Bea, Lee Mack, Joe Lycett and Harry Hill, TV presenters Stacey Solomon, Melanie Sykes and Bill Turnbull, writer and actress Roisin Conaty and Kaiser Chiefs star Ricky Wilson.
Also taking part are Countdown host Nick Hewer, actors Martin Kemp and Griff Rhys Jones, Made In Chelsea star Jamie Laing, singer Ella Eyre, Paralympic gold medallist Kadeena Cox and Diversity dancer Perri Kiely.
The charity Bake Off will take place across five episodes, with each instalment seeing four stars battle it out over three rounds in a bid to be named Star Baker.
As in the regular series, the contestants will have to take part in a signature challenge, a technical challenge and the grand finale, the showstopper.
The forthcoming celebrity special mirrors The Great Sport Relief Bake Off, which aired for three series on the BBC prior to the show being bought by C4.
Previous star contestants on the BBC’s charity spin-off included Geri Horner, Ade Edmondson, Michael Ball, Will Young and Samantha Bond.
The Great Celebrity Bake Off for Stand Up To Cancer will air later this year.