Jacob Hunter, 17, from Bolton-on-Dearne, has limited mobility and sometimes has to use a wheelchair to get around.
He had an operation to straighten his legs and intensive physio as he grew up but is determined to walk the one mile route at Clifton Park in Rotherham on December 13.
Jacob, who celebrates his 18th birthday next month, said: “I’m really looking forward to this challenge and helping the patients and their families who are being looked after by Rotherham Hospice.”
The event, now in its sixth year, saw 400 people dressed as Santa draw in more than £8,500 last year.
The run will set off from the Walled Garden at noon.
Hospice events fundraiser Claire White said: “The Santa Dash is great fun, and you don’t even need to dash. Many people will jog, walk or enjoy a gentle stroll. It’s a fantastic spectacle to see all the Santas together.”
Plenty more dashing Santas are needed for the festive frolic around the park.
Registration is £7.50 for adults and £5 for children, including a free Santa suit to wear during the event and a medal at the finish.
Visit rotherhamhospice.org.uk or contact the fundraising team on 01709 308917.
To donate to Jacob’s challenge, see www.justgiving.com/Jacob-Hunter.
All funds are in aid of Rotherham Hospice.