Seventy Seven PR won a three-way pitch against Publicasity and Trimedia for the account.
The agency will be in charge of creating a 'big bang' launch in mid-September to encourage the public to request fundraising packs. It will also handle media around the telethon, which takes place on 20 November and is presenter Terry Wogan's 30th appeal.
PRWeek understands this year's theme will be encouraging people to 'do something different' to raise money for the children's charity.
Seventy Seven PR will be in charge of recruiting celebrities to raise the appeal's profile in the media, managing a national consumer campaign and handling regional stories. The campaign is expected to include stunts and a heavy focus on digital media. The agency will also have to launch new merchandise.
Last year's appeal brought in £21m on the night, which is expected to rise to a total of £36m by the end of the appeal.
Earlier this year, Seventy Seven PR was appointed to deliver a consumer campaign for pregnancy charity Tommy's. Other charity clients include RSPCA, Royal Blind, Sing Up and Youth Music.
Another well-known charity telethon, Comic Relief, has just announced it raised a record £80m this year. This is a huge increase on previous events despite the recession. In 2007, the total fundraising figure was £67m.