The DJ will try to beat Simon Mayo's record of 37 hours, which was set in 1999. From 6.30am on March 16, Moyles - who was one of nine celebrities who climbed Mount Kilimanjaro for Red Nose Day in 2009 - and his sidekick 'Comedy' Dave Vitty will take over the station to better the previously-set time.
Throughout the day, the duo will guest-host the regular show - whose presenters will join them in the studio.
"In 2009 I broke the record for being the longest serving Breakfast DJ on Radio 1, so I thought, why not go for broadcasting the longest radio show on Radio 1 too!" Moyles said. "Of course I'm worried about what the lack of sleep will do to me, but the pain will be worth it if we can raise a fortune for Comic Relief."
Vitty added: "I'd love to say I'm really excited about it, but every time we talk about the project I feel tired and start yawning!!"
The pair will be allowed to take a five-minute break each hour, or they can save it up and enjoy a longer break. Their attempt will also be broadcast live via the Red Button and online.
Radio 1 controller Andy Parfitt said: ''Last week Radio 1 listeners raised over £500,000 for Red Nose Day - once again our listeners have been amazingly generous. Time and time again they surpass our expectations and I know they'll get behind Chris and Dave as they embark on this amazing challenge."