In response to urgent global sustainability challenges, Education for Sustainable Development (ESD) and Global Citizenship Education have been prioritized in the United Nations’ Agenda 2030 under SDG 4.7. There is a growing awareness that treating concepts such as global citizenship, sustainable development, climate urgency, and health and well-being as separate subjects or topics to be added to a curriculum is ineffective as they are highly interconnected. Additionally, this approach is problematic as schools already have an overcrowded curriculum. This edited volume brings together a range of scholars and reflective practitioners from across the globe who are investigating and enacting a whole school approach (WSA) in education for sustainability. While the WSA and related approaches, such as those advocated by EcoSchools, are becoming more popular, there is a lack of understanding of their underlying principles and the different manifestations in diverging socio-cultural contexts at different educational levels. This collection of chapters provides a deeper understanding of the WSA, while also addressing its effectiveness, possibilities for upscaling, professional development needs for WSA practitioners, interlinkages with more conventional curriculum requirements, expectations of students and parents, and more. This is an open access book.