The family of Bradley Lowery said they are "mega excited" at the official launch of a charity in his name.
His mother Gemma Lowery said money raised would be spent helping children with cancer after the Bradley Lowery Foundation was officially registered.
Sunderland fan Bradley died from a rare type of cancer on 7 July having been diagnosed when he was 18 months old.
His plight touched thousands of well-wishers and a crowdfunding page has so far raised almost £400,000.
Mrs Lowery said the Bradley Lowery Foundation had now officially become a registered charity.
"We're mega excited to announce that after a lot of behind the scenes work, we've got a registered charity number for the Bradley Lowery Foundation," she added.
"We're hoping to support, advise and encourage families on their fundraising campaigns to reach their target and get their child medical treatment and equipment.
We'll give out some grants, but we'll also spend time building rapport with families to support them in all kinds of different ways."
'Tough few years'
Mrs Lowery said it was hoped that the money would also help run a holiday home for families dealing with cancer.
Bradley became a mascot for the Black Cats in the months before he died at the age of six and struck up a close friendship with the club's former striker Jermain Defoe.
Last year his family hoped he would be able to have antibody treatment in New York, but medics then found his cancer had grown and said his illness was terminal.
Mrs Lowery added: "I'm extremely proud to get to this point and take Bradley's legacy forward. It's been a really tough few years.
"The foundation has given me something to focus on and challenge my positive energy into, knowing that my baby has helped and will continue to help so many other children."