The Big Lottery-funded Fixers, whose president is the veteran broadcaster Sir Martyn Lewis, is understood to have faced challenges following changes to its funding arrangements in recent years.
The charity's broadcast arm, which aired inspirational news features about young people across the ITV regions every month, ceased to operate last autumn, but the charity continued to run creative youth projects.
In a statement on its website, chairman Ralph Bernard said that the organisation - registered as the Public Service Broadcasting Trust - has begun a three-month wind-down.
The statement explains that the board of the charity had tried to make the charity sustainable through restructuring, a new strategy and fundraising but was unable to raise enough to support the charity into the future.
Tributes poured in on Twitter, following the charity's pledge to leave a "legacy" for youth work.
It is with great sadness we announce the decision to begin an orderly wind down of Fixers, resulting in its closure in August.
— Fixers (@FixersUK) May 23, 2019
Our focus is on ensuring the young people we work with are supported during this period & to building a legacy.
Read more here https://t.co/mUk8JuDZyQ pic.twitter.com/lF9k8WHzWA
Fixers was established in 2008 and since then has helped more than 23,000 16- to 25-year-olds campaign on issues affecting them using digital, print and broadcast media.
Projects encouraged young people to turn their challenging experiences into something positive - covering topics such as policing, crime, race, sexuality, disability and disadvantage.
The charity said it will fulfil its outstanding obligations to current funders.
Staff will also seek to rehouse the library of resources created over the past 11 years.
Fixers has also pledged to work with the young people currently supported by the charity to ensure they are signposted to alternative agencies.
It said there are also sufficient funds to ensure Fixers can consult with all staff and manage an orderly redundancy process.
"This has not been an easy decision and we would like to thank all staff, past and present, for their dedication and commitment to the charity over the years," said Bernard.
Tweets expressing sadness at the news came from past participants and supporters, including Sharon White, chief executive of the school nursing association SAPHNA.
White tweeted: "So sorry; a travesty. We have done such grt work with u resulting n amazing improved outcomes & outputs 4 many young people. You have mentored & supported many through cathartic care & made a huge difference. School nurses have benefitted from resources & learning".
Housing officer Scott Tandy said:
Sorry to hear this, you guys done some incredible work. The young people you supported in Rhydyfelin still talk about our community hero project we done with you
— Scott Tandy (@Scott_Newydd) May 25, 2019
Dev Sharma, former chair of the Young People's Council, praised Fixers for their help with the Children's Future Food Inquiry.
Sharma said: "Thank you so much to Fixers for all the work they've done with young people like me especially around food poverty and the @CFFinquiry. Nothing would be possible without the hard work and endless determination of Fixers".
Earlier this month, sexual health charity FPA announced it had ceased trading was being placed into voluntary liquidation.
