Also facing down judges John Torode and Gregg Wallace are journalist Janet Street-Porter, Bottom comedian Ade Edmondson and rapper Speech Debelle.
Back on July 31, the first week will see a battle of the ladies as Heidi, Jo, Janet and comedienne Katy Brand will face six culinary challenges over two days.
Running for six weeks – four groups of celebs will take on tasks on the Wednesday and Thursday hour-long shows, with them serving their best two courses in the quarter finals on Fridays.
John and Gregg will be joined of Fridays by 2011's champion Lisa Faulkner (and John's girlfriend – top fact), 2011 winner Phil Vickery and finalist Andi Peters.
The last two weeks will see eight remaining chefs battle it out for foodie victory.
Other contestants include, ex-Coronation Street stars Denise Black and Brian Capron, actor John Thomson, Olympian Phillips Idowu, Les Dennis, boxer Joe Calzaghe and former cricketer Matthew Hoggard.
In the meantime, you can get practising with these MasterChef recipes...
MASTERCHEF RECIPE: STACKED PEAR & BLACKBERRY CAKE
MASTERCHEF RECIPE: CHOCOLATE FONDANT
LIFE SKILLS: HOW TO MAKE HOLLANDAISE SAUCE
SHELINA PERMALLOO'S GINGER KEY LIME PIE RECIPE