This research examines the factors influencing green purchase intention (GPI) among Indonesian consumers, particularly in the cosmetics sector, by focusing on green brand positioning (GBP), green self-concept (GSC), green self-identity (GSI), and attitudes toward green brands (ATGB). The Body Shop is used as a case study of a brand leveraging sustainable practices to attract eco- conscious consumers. Using the Theory of Planned Behavior (TPB) framework, the study explores both direct and indirect relationships between these variables. Valid responses collected via Google Forms were analyzed using partial least squares structural equation modeling (PLS-SEM). The results reveal that GSC significantly influences GSI, which in turn affects GPI. GBP positively impacts ATGB and enhances GPI through better attitudes toward the brand. These findings emphasize the role of psychological factors and branding strategies in promoting green consumer behaviour, offering valuable insights for businesses, marketers, and policymakers in Indonesia's sustainability efforts.