Europe is facing a mental health crisis that will last for decades, impacting the long-term health outcomes, wellbeing and economic productivity of our current generation of young people. Yet, large-scale, comparative research of youth-friendly mental health interventions is lacking. The YOUTHreach consortium aims to bridge this gap and provide a comprehensive European strategy. For this purpose, YOUTHreach will evaluate the clinical effectiveness and cost-effectiveness of three existing and accessible innovative interventions for prevention and early intervention of mental ill-health in youth, developed and tested in co-creation with youth: 1) YEAH, walk-in youth mental health support centres; 2) SELFIE, a transdiagnostic blended ecological momentary intervention; and 3) MOST, a clinical and peer-moderated digital youth mental health platform. In addition, feasibility and acceptability at new sites across Europe will be tested. Furthermore, in partnership with young people, best practice recommendations will be developed based on existing and new data and built into an integrated European youth mental health framework. Finally, awareness and accessibility of these interventions among policymakers, healthcare professionals, the general public, and youth—the target group—will be raised. YOUTHreach aims to contribute towards transformation of the present traditional mental healthcare system and providing the next generation with a better perspective in terms of health, wellbeing and productivity.