We live in a time of burgeoning global population, social extremes and cultural complexity for which, as a species, we are poorly prepared. The mining of fossil fuels and the extractive industries which have powered this reproductive and material success have accompanied our ever-increasing separation from nature, one another, and ourselves. This study is based on the premise that educational transformation, centred on Sustainable Wellbeing, particularly in senior secondary schooling, is crucial to the regeneration humanity needs in the Anthropocene to surmount the complex environmental, social, and cultural crisis that our collective ignorance has brought. It explores what a Sustainable Wellbeing Metacurriculum (SWM) framework for this age group—inspired by a Complex Systems Theory, Critical Realist, and New Materialist synthesis—might look like and what practices, strategies, and changes within schools, communities, and Aotearoa New Zealand as a nation would encourage the metacurriculum’s widespread adoption. The study examined theoretical positions regarding sustainability, wellbeing and curriculum, and drew on the principles of fractal self-similarity and scale-free social networks from Complexity Theory to construct an initial minimal framework. This framework was then elaborated, modified and tested, in an iterative co-construction process. The research design was a modified Delphi Survey. Twenty-three experienced secondary school teachers with a wide range of subject specialities contributed to the study, participating in one to three survey rounds, and/or semi-structured interviews. These data were supplemented with document analysis and school demographic and academic attainment data. Participants were asked for suggestions of Knowledge, Issues, and Big Ideas most important to include within each of the three framework domains; Ecosphere, Social Justice, and Cultural Vision, at the Human-Societal level of an SWM. Within the corresponding domains of Action, Feeling, and Thinking at the Individual-Interpersonal level, the teachers were asked for suggestions of skills, competencies, and dispositions important for students' wellbeing. At the Human-Societal level, nine subdomains, each with sets of Sustainable Wellbeing goals following a complex fractal pattern, self-similar to the domains, emerged from the analysis of suggestions. At the Individual-Interpersonal level, similar fractal patterns for Action, Feeling, and Thinking were observed. However, teachers also emphasised deep qualities, such as Self-Awareness, and Adaptability, which are unique idiosyncratic integrations of Action, Feeling, and Thinking in individuals. The participants were asked to consider the ideal balance between Cross-curricular Holistic (CCH) and Subject-Based Specialist (SBS) modes of pedagogy for an SWM timetable. The mean suggested timetable share for the CCH mode was 39% but the distribution of preferred proportions was distinctly bimodal. Participants were also asked to provide teaching Unit outlines based on the emerging SWM framework that linked the Unit’s anchoring and connected Human-Societal level subdomains to specific learning areas of the New Zealand Curriculum (NZC) and New Zealand’s National Certificate of Educational Achievement (NCEA). Epistemic links were apparent between the framework’s Ecosphere subdomains and the NZC learning areas of Technology, Social Science, Science and Health & Physical Education. Further research with a larger sample of Units would be required to explore the possible links between the framework domains of Social Justice and Cultural Vision and the NZC learning areas of the Arts, Languages, English and Mathematics. The thesis adopts an analogy, based on the complexity theory concept of strange attractors, to describe educational transformation as a system phase shift from the attractor’s current ‘Business as Unsustainable’ state to an emergent Sustainable Wellbeing Metacurriculum state. Based on the findings, the schools of the participating teachers in this study were categorised as following one of four types of trajectory within the attractor, relative to the SWM state i.e. Explorative, Innovative, Prospective, or Realpolitikal. Key strategies used by Explorative and Innovative schools which are making the most progress towards Sustainable Wellbeing include: working with the willing; disaggregation into streams for large schools; aggregation for small schools sharing resources, like gardens; school and teacher leadership for student agency, including making Sustainable Wellbeing a core subject; Trades Academy partnerships; enabling ‘student voice’ particularly in curriculum development; structural support for CCH team teaching; involving a wide range of subjects and year levels in CCH programmes; using mentoring, portfolios and self-reflection to foster student self-integration; and commitment to on-campus sustainability practices. The most mentioned changes needed to enable a transition for schools to enact an SWM were a convincing argument and plan, followed by, sufficient time to plan and make the changes required, and the provision of relevant teacher training. At the local community level, teachers in ‘Prospective’ schools described community anxieties around the implications of a broader CCH curriculum for students' Qualification and Employment prospects. Teachers in ‘Explorative’ schools emphasised the importance of community education and school outreach. There was a strong consensus that engaging all citizens in a conversation about the purpose of education in our time would be the most effective change strategy to support at the national political level.