This article assesses the impacts of individual-level environmental attitudes and national-level environmental governance on individual sustainable consumption. Multilevel analysis based on data from 31 countries shows that three key environmental attitudes, environmental concern, environmental efficacy, and perceived environmental impact, are all positively associated with sustainable consumption behavior. Environmental governance is found to have different impacts in high-income compared with other countries analyzed. In high-income countries, effective environmental governance encourages people to participate in sustainable consumption, whereas it discourages people’s participation in other countries. In addition, in high-income countries, people with strong proenvironmental attitudes are more likely to consume sustainably in the face of weak environmental governance; in other countries, however, the attitude–behavior association is strengthened in the face of effective governance. The results highlight the importance of individual attitudes and the broader context in influencing proenvironmental behaviors, and suggest that sustainable consumption should be understood as a social process accomplished through collaboration between individual consumers and institutions.