Online consumer privacy concerns are among the most persistent barriers to digital commerce, yet they vary substantially across countries. This study develops a cross-national framework explaining how cultural values (e.g., individualism–collectivism, uncertainty avoidance), institutional factors (e.g., regulatory strength, trust in government and firms), and digital-marketplace practices (e.g., personalization intensity, tracking transparency, and consent usability) jointly shape privacy concern levels and downstream behaviors. Drawing on Communication Privacy Management theory and the privacy calculus perspective, we propose a model linking cross-national antecedents to privacy concerns, perceived control, and behavioral outcomes such as information withholding, ad avoidance, opt-out usage, and platform switching. We outline a comparative research design using measurement invariance procedures to enable valid cross-country comparisons and propose hypotheses for future empirical tests. The paper provides managerial guidance for designing culturally sensitive privacy experiences and policy insights for harmonizing privacy governance while respecting local norms.