["Corporate Social Responsibility and Environmental Management, EarlyView. ", "\nABSTRACT\nResponsible consumption and production, emphasized in Sustainable Development Goal 12 (SDG 12), require both company‐level sustainability initiatives and an understanding of how consumers respond to corporate responsibility signals. Environmental, Social, and Governance (ESG) framework has become a central mechanism through which companies communicate their commitment to sustainable development; however, the behavioral pathways that link ESG perceptions with consumer behavior remain under‐researched. This study examines how consumers' perceptions of companies' ESG engagement shape sustainable consumption through the mechanisms proposed by the Theory of Planned Behavior (TPB). Using survey data from a nationwide sample of 1000 consumers across four generational cohorts, the model is tested with partial least squares structural equation modeling and multigroup analysis. The results indicate that perceived ESG engagement acts as a structured antecedent that influences attitudes, subjective norms, and perceived behavioral control, which subsequently shape behavioral intention and actual sustainable consumption. Attitudes emerge as the dominant mechanism, indicating that ESG‐aligned consumption is largely value‐driven, while normative and control‐related factors play complementary roles. Although behavioral intention significantly predicts actual behavior, an intention–behavior gap remains. Generational differences are limited and mainly concern the translation of intention into behavior. By integrating ESG into TPB, the study provides a behavioral micro‐level explanation of how company‐level ESG engagement supports the objectives of SDG 12.\n"]