Dame Kelly Holmes and Ellie Simmonds will lead two teams of celebrities and sports stars during an all-star version of the Commonwealth Games.
The hour-long BBC special in aid of Sport Relief will be a companion to the actual 2022 Games, which are taking place in Birmingham this summer.
The All-Star Games teams will be put through their paces as they take on five sports in front of live crowds at the same venues used during the Games.
The teams will compete in track cycling at the Lee Valley Velopark, athletics at the Alexander Stadium, rhythmic gymnastics at Arena Birmingham, basketball 3×3 at Smithfield, and table tennis at the NEC Arena.
The full celebrity line-up will be announced at a later date.
Two-time Olympic champion Dame Kelly, 52, said: “I love seeing people getting involved in sport and giving things a go – getting out of their comfort zone and just having fun.
“This competition is right up my street and it’s a real honour to be leading the red team.
“I’ve been a supporter of Sport Relief for such a long time now and know the work they support is completely life-changing.
“I hear Ellie is determined for her team to win but I don’t fancy her chances.”
Former Paralympic swimmer Simmonds, 27, said: “I’m so excited to lead the blue team in the All-Star Games and feel really proud to be supporting Sport Relief again.
“I’ve been involved in Sport Relief for years, but I know this is going to be the most fun.
“I can’t wait to get the team into training and make sure we all work really hard to raise as much money as we can… but also win.
“As much as I respect and admire Kelly – she’s such an incredible role model for young athletes – I’ll leave that at the door. Winning is all that matters. Bring it on.”
Sport Relief is an official charity partner of the Commonwealth Games and hopes to raise money to tackle issues including inequality and mental health.
Samir Patel, chief executive of Comic Relief, said: “I hope as many viewers as possible tune in to see our fantastic celeb champions compete.
“If you enjoy the show and are able to donate you’ll be helping us raise money for vital projects.
“Partnering with Birmingham 2022 Commonwealth Games is the start of a brand-new era in Sport Relief’s 20-year history.
“We’re excited to harness the incredible energy of sport to raise money and change lives for the better all year round.”