The aim of this study was to explore the impact of social class on individuals’ participation in protest actions, focusing on socio-environmental mobilizations on the Island of Chiloé, southern Chile, in 2016. We conducted a quantitative cross-sectional study, surveying a random sample of 400 adults from the island’s two main cities. Our analysis utilized a structural equations model to integrate traditional predictors from social psychology with class position—a factor not commonly considered in such research. Contrary to our hypothesis, the results revealed that individuals from higher and middle social classes were more likely to participate in the protests. These findings challenge common assumptions about the demographics of protest participation and underscore the complex interplay between social class and collective action. The implications of these results are particularly relevant for understanding the dynamics of socio-environmental movements and for formulating strategies to engage diverse community segments in such actions.