The Sustainable Development Goals (SDGs) are gaining prominence on the international policy agenda, which is enabling organisational sustainability. It is increasingly recognised that organisations can pursue outcomes aligned with the SDGs by engaging a wide range of stakeholders at a local level, which collectively has the potential to facilitate global action. Social and Solidarity Economy (SSE) organisations offer a holistic approach to inclusive sustainability. Given their primary focus on social and environmental purposes rather than profit maximisation, SSE organisations have the potential to explore behaviour and measure impacts that local stakeholders can better understand. This study explores the experience of Kendal Mountain Festival and the Lake District Pound, two SSE organisations based in Northwest England. Action research is used to examine beliefs and behaviours within these SSE organisations, and to assess their impacts on key stakeholders. Both organisations seek to integrate sustainability into their business models and influence stakeholders to generate behavioural change. Differences and similarities between the organisations are addressed, including: challenges and opportunities facing emerging versus more established organisations; variance in context, purpose, vision and values; and the extent to which the organisations and stakeholders are integrating the SDGs into their thinking and practice.