Following indications from international organizations, this study tests the associations between the five domains of social, emotional, and behavioral (SEB) skills (self-management, innovation, social engagement, cooperation, and emotional resilience) and two key antecedents of proenvironmental behavior, namely nature connectedness and self-perceived action competence for sustainability, in a sample of 702 students aged between 12 and 20 years (M = 16.18, SD = 2.15; 319 males). Results showed that innovation skills and--to a lesser extent--self-management and cooperation skills are positively associated with both nature connectedness and action competence. An additional exploratory path analysis suggested that the association between SEB (innovation, self-management, and cooperation) skills and proenvironmental behavior could be mediated by action competence and nature connectedness. The study offers new insights into the antecedents of proenvironmental attitudes and behaviors in youth.