Baroness Tanni Grey-Thompson will light the Rio 2016 Heritage Flame during a televised ceremony at Stoke Mandeville stadium.
The 47-year-old, who won 11 Paralympic golds as a wheelchair racer across four games, will take centre stage at Friday’s event.
The Heritage Flame Lighting Ceremony is part of the lead-up to the Paralympics in Rio.
Stoke Mandeville, the birthplace of the movement, is the only venue outside Brazil to play a role in marking the start of the games.
Baroness Grey-Thompson, who is a member of the House of Lords, said: “It’s going to be an incredible ceremony and really nicely thought out.
“I’m really excited about being there - it’s going to be very moving,” she said.
“I spent most of my childhood at Stoke Mandeville. It’s such an important part of the Paralympic movement and it’s great it’s being recognised around the world. It’s where it all began.
“It’s going to be a massive celebration and a really good party. People should come along – it shows the support for the Paralympics and it’s a great way to wish good luck to Paralympics GB.”
An audience of 1,400 will be at the stadium for the ceremony and thousands more will be celebrating in a carnival atmosphere in Vale Park.
Baroness Grey-Thompson was born with spina bifida and joined the British Wheelchair Racing Squad aged 17, first competing in the Paralympic Games at Seoul 1988. She broke 30 world records during a glittering career.
Penny Mordaunt, minister of state for disabled people, work and health, said: “This will be a fantastic celebration of the Paralympics and their importance in transforming global attitudes to disabled people.” Tim Reddish, chairman of the British Paralympic Association, said it was important for the growing Paralympic movement to ‘honour its birthplace’.
Martin McElhatton, member of the Bucks Legacy Board, said the ceremony will celebrate the ‘inspirational vision’ of founder Sir Ludwig Guttmann. He thanked Arts Council England for helping organise what will be a ‘truly memorable occasion’.