The ex-Special Forces operatives return to test twelve brave celebrities in an intense seven day course.
The stars will be pushed to the extreme under the watchful eyes of Chief Instructor Ant Middleton to see who could make it in the SAS, in a five-part special for Stand Up To Cancer.
Best known for taking gold during the Beijing and London Olympics, cyclist Victoria Pendleton also won nine World Championship gold medals during her career.
Pendleton has since switched saddles to compete as a professional jockey.
She’s no stranger to hostile environments, after last year attempting to summit Mount Everest with TV presenter Ben Fogle (she was forced to quit due to oxygen deprivation).
Speaking about her latest challenge with the Radio Times, Pendleton said: “The biggest thing about this is whenever I’m training or going into a competition, I know it’s got a start and an end and what I have to do,” she said. “With this, we had no idea. You’re on edge the whole time.”
Actor Jeremy Irvine is best known for starring in Steven Spielberg’s adaptation of War Horse, and more recently portraying a younger version of Pierce Brosnan’s character Sam Carmichael in Mamma Mia! Here We Go Again.
As a long-time fan of SAS: Who Dares Wins, Irvine isn’t afraid to push himself to the extreme.
During his time on The Railway Man, the actor lost two stone and even gave permission to be waterboarded.
Retired footballer Wayne Bridge played left back for some of football’s biggest teams including Chelsea, Manchester City and Southampton, and represent England in two World Cups.
Bridge is no stranger to pushing himself on reality television, having eaten creepy crawlies on camera in I’m a Celebrity…Get Me Out of Here! landing him in sixth place.
"I don't like to fail and don't like to let people down," said Wayne Bridge when discussing what he fears from the show.
"That was probably my biggest fear, not being able to do it."
He may have survived the jungle, but how long will he last in the SAS camp?
Host of 4Music show Trending Live!, AJ Odudu is also known for co-hosting Big Brother’s Bit on the Side with Emma Willis and Rylan Clark.
During training, Odudu will be pushed to her limits as the show’s tasks prove physically and mentally challenging.
Jeff Brazier first appeared in Channel 4’s Shipwrecked in 2001 and has since worked as a presenter on This Morning, I’m a Celebrity… Get Me Out of Here! Now and Sunday Scoop.
“I found far more than I bargained for,” said Brazier of his SAS experience. “You’ve got fear rife and coursing through your veins but you have to put one step in front of the other.”
"The fact that it’s going to raise money is just an amazing cherry on top," added Jeff Brazier.
"I would have literally paid thousands of pounds to have gone out there and done it, which sounds ridiculous given the amount of pain and discomfort that I experienced as a result, but it gave me a better knowledge of myself and who I am today."
Rugby player Heather Fisher overcame anorexia to compete in Rugby Union and Rugby Sevens, and to represent England in the Women’s Rugby World Cup.
Having suffered severe alopecia, Fisher has appeared on E4’s Body Fixers and is an ambassador for Alopecia UK.
"I'm going to prove that women can go toe to toe with men," stated Heather Fisher.
"That was my motivation."
"But then when it got mentally tough I had to remember what this was for, some people would never get the chance to do what I do because of their illness."
Novelist and former Conservative MP made headlines during her time in Parliament when she took a strong stance against phone-hacking.
“When a producer rang and asked why I thought I’d be good in the special forces, I replied, ‘I won’t be, I’m not a moron!’” Mensch joked.
“But for most of us it was about the honour to be in front of guys who had risked so much for this country.”
Loose Women presenter Andrea McClean will be the oldest contestant to appear on the show.
McLean started her career as a weather presenter on GMTV before moving on to hosting daytime programmes including LK Today and Our House.
Rugby star Ben Foden played for the Northampton Saints before moving to the US to play for Rugby United New York.
Off the pitch, Foden has shown off his singing talents in a celebrity special of BBC One’s All Together Now, and earned himself the nickname ‘Pops’ after once missing training to audition for Pop Idol.
"Obviously doing rugby put me in a good state of mind for the challenges like going up mountains, carrying heavy loads, and things like that," said Ben Foden.
"The mental side of it all was always going to be the bit that was going to be testing for me. I've always been one of those athletes that probably wasn't mentally the toughest."
Reality star Camilla Thurlow is most famous for appearing on ITV2’s Love Island in 2017 where she coupled up with Jamie Jewitt in the villa.
Thurlow will prove a strong competitor for the SAS challenges having worked in Explosive Ordnance Disposal in conflict zones.
Radio 1 DJ Dev Griffin will swap the sound booth for the SAS trials.
Griffin currently hosts his own afternoon weekend show on Radio 1 and regularly covers for Greg James and Scott Mills.
The radio presenter started out in presenting the children’s TV show Smile with Fearne Cotton and co-hosting a Saturday afternoon show on 1Xtra with Reggie Yates.
Dev Griffin commented about his time on the show: "Every time I had a low moment or just felt like I physically couldn't do anything, the fact we were doing the show for such a good cause is what I kept coming back to and it kept me motivated."
Finding fame on Made in Chelsea, reality star Sam Thompson appeared on Celebs Go Dating and Celebrity Big Brother in 2017.
"I've been pretty lucky in my life," said Sam Thompson.
"I’ve never really pushed my boundaries to the limit before. I really think that's a very big part of growing as a person, seeing exactly what your limit is and if you can surpass it."
Thompson’s posh-boy charm may have helped him find love on Celebs Go Dating but how will the DSs take to the reality star when it comes to the challenges?
Celebrity SAS: Who Dares Wins starts on Channel 4 on Sunday 7th April at 9.00pm.