Global overconsumption undermines social, environmental, and personal well-being. Consumer minimalism offers a solution through reduced and thoughtful consumption. Additionally, adopting responsible financial behavior is crucial to avoiding the negative effects of overconsumption. The aim of doctoral research is to test a theoretical framework for empowering consumer minimalism among adolescents and to develop behavioral interventions to reinforce it, which will be tested through an experiment. The study also explores the relationship between consumer minimalism and responsible financial behavior in adolescents. The research was conducted in-person in high school classrooms across Croatia, with a random sample of 661 high school students. The research concluded that capability, motivation, and opportunity, as determinants of consumer minimalism, are positively associated with consumer minimalism in adolescents. Thus, it can be inferred that the behavioral determinants covered by the COM-B model successfully form consumer minimalism. Additionally, a strong positive association was found between consumer minimalism and responsible financial behavior, suggesting that consumers, through thoughtful, reduced, and frugal spending, can achieve financial control and potentially enhance both financial and overall personal well-being. In the context of testing behavioral interventions, their effectiveness was confirmed, as each intervention positively impacted at least one determinant of consumer minimalism.