The main objective of the Science Education for Action and Engagement Towards Sustainability (SEAS) is to establish, coordinate and evaluate collaboration among six open schooling networks led by universities and science centres with partners in Austria, Belgium, Estonia, Italy, Norway, Sweden, and the UK. As part of these networks, and drawing on principles of inquiry-based science learning for transformative engagement, students in formal schools are given the opportunity to engage in addressing real-life, complex sustainability challenges that are identified and dealt with together with participants and stakeholders in the local community. SEAS develops and makes us of models for open-schooling implementation that supports schools and out-of-school institutions to collaborate in the promotion, among students and citizens in the larger community, of 21st century scientific literacy and skills for responsible citizenship. SEAS delivers enhanced opportunities for students and citizens to develop deeper interest in science and inclusive scientific literacy, both in the target communities and beyond them taking into account gender, socio-economic status and geographical differences. By providing facilitation and mediation tools and methods for the identification and implementation of sustainability challenges in the participants’ local communities, SEAS makes it possible for students to collaborate with families and stakeholders from civil society and industry in becoming agents of community well-being. SEAS provides participants with the necessary expertise, networking, and sharing resource experience to address these challenges and, in doing so, develop deeper scientific literacy skills and interest in science education and careers. SEAS also contributes to generating models and experiences for ways in which science education inside and outside of the school may become part of the solution to some of the greatest challenges of our times.