The charity said it is working with the Royal Mail to launch the Blues Programme, a preventative course designed for young people nearing the end of school who are showing early signs of anxiety, depression or other problems.
The programme, which was developed at the Oregon Research Institute in the United States in 2008, will initially be delivered in selected schools and colleges in Buckinghamshire, Worcestershire and Cardiff, before being introduced across the UK, with the aim of eventually reaching 8,000 15- to 18-year-olds.
Action for Children will employ specialist youth workers, known as "Blues Busters" to deliver face-to-face support sessions. It is hoped that the skills and knowledge passed on will provide young people with cognitive restructuring techniques to identify and challenge feelings that cause anxiety, as well as an understanding of coping strategies and how to apply these skills to life.
Sir Tony Hawkhead, chief executive of Action for Children, said: "We are committed to making sure that any child who needs help gets help and selected this programme with our partners at Royal Mail because it has a proven track record in the USA.
"Feedback shows that in many cases it helps to prevent the onset of serious depression and supports young people to feel healthier, happier and get involved in more positive activities.
"This is a fun and engaging group-work programme that works with young people to help them to understand why they are feeling down and find ways to improve the way they feel.
"With the support of Royal Mail, we hope to make this programme accessible to more schools and organisations next year."
Lily Heinemann, head of corporate responsibility at Royal Mail, said the organisation hopes to raise around £4m to fund the programme.
"This will enable Action for Children to employ specialist youth workers to deliver face-to-face support sessions for 8,000 young people aged 15 to 18 to help prevent them from developing depression and other mental health problems," she said.
"Mental health is such an important issue for our business and our people, many of whom are parents and carers of young people themselves. We are excited and privileged to be working with the charity to help tackle the growing problem of poor mental health affecting young people."
Michael Kitkat, principal at Worcester Sixth Form College, one of the colleges piloting the scheme, said there is often limited access to mental health support services, and lengthy waiting times for young people, due to financial pressures currently facing local authorities.
"We are really excited at Worcester Sixth Form College to be able to participate in this early intervention pilot to support students who are showing early signs of anxiety and depression.
"Our young people complete a survey that seeks to identify if they are showing early signs of poor mental wellbeing or are at risk of developing problems.
"Those identified as showing early signs are then offered a place on a six-week course which involves weekly one-hour group sessions on site, together with work at home to support this. It's open, upfront and supportive - there's no stigma."