In this article, we investigate which personality dimensions provide a common psychological basis for environmental measures and socio-moral orientations (e.g., feeling connected to others, perceiving the environmental problem as moral). In a cross-sectional study (N = 634), we explored the associations between the HEXACO dimensions and a wide range of environmental measures as well as socio-moral orientations related to environmentalism. We found that Openness to Experience was the most prominent predictor of environmental measures, socio-moral orientations, and the belief that climate change is caused by human activity. We further provide a comprehensive overview of how each personality dimension connects socio-moral orientations and environmental measures, highlighting the multifaceted nature of environmentalism. The findings underscore the role of individual differences in coping with the environmental crisis. Our article replicates and extends previous research, contributing to the ongoing discussion on how differences in individual predispositions influence environmental engagement.