Investigating Good Practices for Implementing the 17 SDGs in Greek Secondary Schools by 2026

The integration of the United Nations' 17 Sustainable Development Goals (SDGs) into secondary education systems has been recognized as a critical strategy for promoting global sustainability.In the Greek context, a mixed-methods investigation was conducted to identify and evaluate effective practices for embedding the SDGs in secondary school settings by 2026.Drawing upon the theoretical frameworks of Education for Sustainable Development (ESD) and Experiential Learning Theory (ELT), the study sought to examine the extent to which institutional leadership, teacher preparedness, curriculum design, and stakeholder collaboration contribute to the establishment of sustainability-oriented education.Quantitative data were collected through surveys administered to 286 secondary school teachers, while qualitative insights were derived from semistructured interviews involving educators, school administrators, and external stakeholders such as NGOs and local community representatives.The findings indicate that leadership support constitutes the most influential predictor of successful SDG implementation, particularly when accompanied by strategic planning and the provision of targeted resources.Teacher training initiatives were found to significantly enhance the instructional capacity for sustainability-focused pedagogies, especially in the context of project-based and participatory learning models.Furthermore, partnerships with non-formal educational actors were shown to facilitate access to additional expertise and learning materials, thereby enriching both curricular and extracurricular initiatives.Programs such as sustainability clubs and interdisciplinary projects were identified as effective mechanisms for fostering critical thinking and applied problem-solving among students.Nonetheless, several systemic constraints-most notably institutional rigidity and limited resource allocation-were observed to impede widespread adoption.It is therefore proposed that by addressing these structural challenges and drawing upon international best practices, Greek secondary schools may achieve more robust alignment with the 2030 Agenda for Sustainable Development.