This study examines the transition of sports organisations networks towards more environmentally sustainable practices through the lens of organisational learning. Leveraging the 5i framework of organisational learning, as well as previous literature on learning for environmental sustainability, the study aims to widen the applicability of theories developed in supply chain inter-organisational networks to non-traditional inter-organisational networks, as well as explore potentially overlooked factors influencing the process of organisations learning for environmental sustainability. A mixed-method approach was adopted, combining quantitative analysis using the Learning Practices Questionnaire (LPQ) with qualitative insights from semi-structured interviews. Quantitative results revealed the prominence of inter-organisational learning processes over individual and organisational levels, underscoring the significance of external networks in addressing resource limitations and driving strategic renewal. Qualitative findings took the analysis further by highlighting three core themes: outward orientation of organisations throughout the learning process, definition of environmental sustainability as a network-level outcome, and factors influencing inter-organisational activities within the network.This study contributes to the field by demonstrating the interplay of network structures, resource dependencies, and relational dynamics in shaping learning processes for environmental sustainability, specifically the definition of environmental sustainability as a network-level outcome. It highlights the need for tailored frameworks that address the unique characteristics of non-traditional networks, providing actionable insights for fostering collaborative learning environments that can drive systemic change. Future research is encouraged to better understand the factors affecting the legitimacy of organisations to participate in defining environmental sustainability for the network, as well as the role of sustainability professionals existing at the intersection of social and organisational networks.