This study explored the role of Education for Sustainable Development (ESD) in shaping sustainable consumption behaviours (SCB) among international students in Japan and South Africa, utilising the Theory of Planned Behaviour (TPB) as a framework. The research aimed to examine how ESD influences attitudes towards sustainability (ATS), subjective norms (SN), perceived behavioural control (PBC), sustainable consumption intentions (SCI), and SCB. A cross-sectional design was employed, gathering data from 265 international students through a structured questionnaire. Partial Least Squares Structural Equation Modeling (PLS-SEM) was used to analyse the data and test the proposed hypotheses. The findings indicated that ESD significantly influences ATS, SN and PBC, which in turn affect SCI and SCB. The influence of ESD on these constructs was stronger among international students in South Africa, potentially due to the country's cultural emphasis on community support and collective action. SCI emerged as strong predictors of actual sustainable behaviours in both contexts, while SN did not significantly influence SCI in either country. The study extends the TPB framework by integrating ESD, highlighting the crucial role of educational interventions in fostering sustainable behaviours. The findings suggest that educational institutions should incorporate comprehensive, culturally adaptive ESD programs to enhance pro-environmental attitudes and behaviours. This research contributes to the understanding of how ESD influences sustainable consumption behaviours through the TPB framework, thus emphasising the importance of cultural and contextual factors in shaping the effectiveness of ESD. The insights offered are valuable for educators, policymakers and businesses aiming to promote sustainability.