Changes in social construction, the growing tendency for globalization, and diverse cultural, linguistic, national, and socio-economic characteristics which took place in the Greek society, coupled with the coronavirus disease (COVID-19) pandemic has led to dramatic changes in quality of life, bringing to the forefront of the debate the question of planning resilient societies. In this context, schools have become the key grounds for the formation of educational policies. Factors within the school environment have been found to have an impact on young people’s mental health and wellbeing. Supportive teacher-student relationships, promotion of students’ social and emotional competences, and teachers’ own wellbeing are related with students’ positive social relations and development of a healthy lifestyle. Therefore, it is important to promote factors which have an impact on young people’s mental health and wellbeing at schools. Current chapter aims to outline a picture of theory, policy, research, and practice of wellbeing in Greek schools. Drawing upon illustrative case studies, we discuss issues including for example that of the National Curriculum and frameworks for promoting wellbeing in schools, research on teachers’, students’, and parents’ perceptions of wellbeing, adaptation of school mental health programs and suggestions for practice and teachers’ professional development. The chapter concludes with the need to address factors to decrease students’ mental health problems, teachers’ stress and burnout and create safe learning environments for both teachers and students.