The decathlon legend will join race organiser, fellow Olympic athlete and good friend, Steve Cram at the weekend of events, which takes place on Saturday October 6 and Sunday October 7, 2018.
Daley, who won decathlon gold medals at the Olympic Games in 1980 and 1984 and broke the world record in the event four times, will also be introducing his new range of DT10 Sports products to Kielder runners.
The range, which includes protein drinks and bars, was developed together with Masterchef Gary Barnshaw, after Daley was disappointed at the high-levels of sugar content in similar products.
Every runner participating in the weekend will receive one of the new DT10 protein bars in their goody bags as they cross the finish line.
Daley will also join Steve for a question and answer session at The Boat Inn restaurant at Kielder Waterside on Saturday night, where competitors will be able to find out more about his legendary track history.
Steve Cram, said: "We′re all really excited to have Daley joining us for this year′s event. As someone who enjoys his cycling challenges now, I′ve been telling him how much he needs to get up to this stunning part of the world and see what Northumberland has to offer.
"1,500m was always a ‘marathon distance′ for Daley at the end of a decathlon, so getting him around 26.2 miles might be a push, but it will be great to have him at Kielder Waterside all weekend, meeting runners and supporters who will remember his extraordinary achievements back in the 80′s!"
The Active Northumberland Kielder Marathon Weekend 2018 is delivered by Events of the North in conjunction with Northumbrian Water, Active Northumberland, Northumberland County Council and Northumbria Healthcare NHS Foundation Trust.
The weekend′s events, which attract runners from all across the UK, are all based around Northumbrian Water′s picturesque Kielder Reservoir and waterside sites and include the Marathon, Half Marathon, 10k and the Run Bike Run.
For more information on the events taking place at Active Northumberland Kielder Marathon Weekend 2018 and to book your place visit www.kieldermarathon.com