Social psychological research on environmental collective action often overlooks the facilitating or hindering impact of a country’s context. The institutional attitudes of governments toward environmental issues can play a crucial role in mobilizing environmental activism. To explore how individual and contextual factors interplay for engagement in environmental collective action, we conducted multilevel modelling using data from 12 countries (n = 18,746). While the engagement in environmental collective action was predicted by stronger environmental concern and environmental efficacy beliefs, the strength of these relationships was moderated by macro-level contextual variables related to political governance. In countries with more effective environmental policies, both environmental concern and environmental efficacy beliefs had a stronger impact on collective action compared to the countries with inadequate environmental governance. Moreover, our findings indicated that environmental concern is less likely to translate into environmental collective action in repressive countries. Findings are discussed within the frameworks of community resilience, identity, empowerment, and repression.