Fresh from winning two gold medals and a silver at Tokyo 2020, the swimmer confirmed he is the 13th contestant to join the line-up of the BBC One series.
He said: “I think this will come as a surprise to a lot of people, but I’m so excited to finally share the news that I’ll be joining Strictly this year.
“I’m really looking forward to doing something totally different and challenging myself away from the pool. I’m hoping my competitive nature is going to compensate for my dancing abilities!”
Peaty helped Great Britain claim a record eight swimming medals, eclipsing their previous best of seven at the 1908 Games, and said he would take a break from the pool to prioritise his mental health.
He joins the line-up alongisde Coronation Street star Katie McGlynn, BBC Breakfast presenter Dan Walker, presenter AJ Odudu, Peep Show’s Robert Webb, McFly star Tom Fletcher and Dragons’ Den investor Sara Davies.
Former Bake Off winner John Whaite will be taking to the dance floor in another first for Strictly as one half of an all-male pairing.
Whaite said his all-male partnership will be a "great step forward in representation and inclusion".
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ITV's Loose Women star Judi Love was also announced on Friday as the latest celeb to don their dancing shoes for the show.
She said: "I think I am still in shock that I will be part of this amazing show.
"I’ve watched it for many years and admired the phenomenal abilities of these dancers and celebrities that have taken part and dedicated themselves to learning a new craft."
'I have broken a world record every single year because I know what is best for me' says Peaty
After Tokyo, Peaty announced he would be taking a break from swimming to focus on his mental health.
He told ITV News: "The thing is, especially being a sportsperson, a lot of people have opinions about you and what's best for you and for me I know exactly what is best for me.
"I have broken a world record every single year because I know what is best for me."
Peaty is an eight-time world champion, a 16-time European champion and a three-time Commonwealth champion.