Young carers are children and adolescents who provide care to other family members or friends, taking over responsibilities that are usually associated with adulthood. There is emerging but still scarce knowledge worldwide about the phenomenon of young carers and the impact of a caring role on their health, social and personal development spheres. This paper provides an overview of the main results from the ME-WE project, which is the first European research and innovation project dedicated to adolescent young carers (AYCs) (15–17 years). The project methods relied on three main activities: (1) a systematization of knowledge (by means of a survey to AYCs, country case studies, Delphi study, literature review); (2) the co-design, implementation and evaluation of a primary prevention intervention addressing AYCs’ mental health (by means of Blended Learning Networks and a clinical trial in six European countries); (3) the implementation of knowledge translation actions for dissemination, awareness, advocacy and lobbying (by means of national and international stakeholder networks, as well as traditional and new media). Project results substantially contributed to a better understanding of AYCs’ conditions, needs and preferences, defined tailored support intervention (resilient to COVID-19 related restrictions), and significant improvements in national and European policies for AYCs.