UPRIGHT (H2020, ID 754919) is a universal preventive resilience-based program to foster well-being and positive school environments. A nine-month co-creation and regionalization stage was deployed in Poland, Basque Country-Spain, Italy, Denmark, and Iceland. The methodology combined participatory, qualitative, and quantitative paired strategies, and targeted the three stakeholders: adolescents, families, and school staff. Nine hundred and seventeen participants answered surveys (adolescents = 340; families = 258; school staff = 125) or attended 16 individualized working session (adolescents n = 89, families n = 51, school staff n = 77). The results show that (1) mental health prevention in schools is highly relevant and opportune according to the adolescents, families and school staff involved (2) UPRIGHT theoretical model of 4 components and 18 resilience skills is pertinent, meaningful and applicable. (3) Adolescents’ concerns must be addressed as part of a resilience-based preventive program (i.e. bullying, self-harm and suicide, loneliness, cyberbullying and life purpose). (4) There are differences between countries in the strengths, expectations, and preferred methods for UPRIGHT implementation. In conclusion, a resilience-based and positive education should be innovative, it must incorporate new technologies, it should connect different actors and communities, and it must acknowledge cultural differences.