Background: At risk young people can be hard to reach and engage in support. Social media has the potential to reach large numbers, however there are very few evidence-based interventions that capitalise on the opportunities social media provides. The aim of this presentation is to describe how one social media intervention (#chatsafe) is being used to reach hard-to-reach, at-risk young people. Methods. The #chatsafe guidelines are designed to help young people communicate safely online about suicide. They were developed in 2018 via a Delphi expert consensus study and are disseminated to young people via a co-designed social media campaign. The efficacy of this intervention has been tested in 2 pilot studies, one with a general population sample and one with young people bereaved by suicide. More recently youth consultations have been conducted to explore whether #chatsafe could deliver real-time support to young people expressing suicide risk online. Results: The pilot studies found #chatsafe to be safe, acceptable and feasible to deliver. It also led to improved confidence communicating online about suicide, improved willingness to intervene against suicide and increased perceived online safety. The intervention now forms part of a real-time postvention response following the suicide of a young person. To date, 53 postvention campaigns have been deployed across Australia and New Zealand via Snapchat, Instagram and Facebook, reaching 2.4 million young people. Young people identified that it would be acceptable to use #chatsafe to deliver evidence-based interventions & psychoeducation to young people at risk and to help them access support services. Conclusions: The #chatsafe intervention has been shown to be safe and acceptable and appears to improve perceived online safety. It can also reach large numbers of people quickly and at little cost. Together these findings suggest that social media offers a useful way of reaching hard-to-reach young people. Next steps will be to co-design and test a suite of content specifically designed for young people expressing suicide risk online and to work with social media platforms to disseminate it in a safe and acceptable way.