Learning disabilities charity Mencap has been chosen to benefit from the annual Blue Peter Appeal.
The BBC children's programme has set an initial fundraising target of £500,000, but the charity hopes to emulate the success of last year's appeal, which raised £1.5m for Wateraid.
The appeal, which launched last week, will support the charity's work helping children with learning disabilities to take part in more out-of-school activities. Many children with learning disabilities are excluded from these activities because clubs can't provide the support that the children need to participate.
"This is a really exciting and important project for Mencap, not only because money will be raised but because, most importantly, it will change people's perceptions of children with a learning disability," said Mencap project manager Claire Brown.
Blue Peter Appeals have been held every year since 1962 and are one of the biggest fundraising campaigns aimed at children. This year, young viewers will be encouraged to raise money for the appeal by holding bring-and-buy sales and designing and selling greetings cards.