Social movements often mobilize individuals from a specific social group or strata, basing their claims on the grievances, interests, and identity of this group. This chapter investigates the class composition of environmental movements. It discusses the social class of those being mobilized to environment-related political participation but not how class matters when environmental movements seek support for their views and claims. The chapter describes collective actions carried out by actors self-identifying as environmentalists, leaving out local or specific campaigns and mobilizations focusing on aspects of the environment without framing this as part of overall environmental struggle. Some studies about environmental attitudes and environment-related political participation have discussed class-related differences in value orientation as an explanation for variation in attitudes and participation. The chapter focuses on the modern environmental movement, which since the 1960s has widened its scope from conservationism to issues like environmental pollution, nuclear energy, climate change, and environmental justice. It utilizes data from World Values Survey to analyze the class composition of members in environmental organizations in the Global South in order to discuss class differences in environmental activism across the globe.