This insightful Handbook provides a comprehensive illustration of contemporary discourse and approaches to teaching and learning for a global society. Leading experts examine the ethical imperative of Global Citizenship Education (GCE) to educate for both human and ecological flourishing. Tracing its evolution, the Handbook contextualises GCE in the current political and social climate and explores its conceptual framings, practical applications and emerging problems, while also distinguishing GCE from related fields through its integrative and action-focused orientation. Assessing questions of power, sustainability and technology, contributors evaluate topics such as studying abroad, human-centered AI and shared languages. This Handbook supports research and practice in GCE, providing innovative frameworks and case studies that highlight current challenges in the field as well as opportunities for future development. The Handbook on Global Citizenship Education is a valuable resource for students and scholars of international education, particularly those with a focus on curriculum studies and global citizenship education. This multidisciplinary Handbook also provides crucial insights for researchers interested in global citizenship and nationalism, as well as practitioners and policymakers looking to improve their understanding of how education contributes to the creation of a planetary society.