In response to growing consumer demand for sustainability, this study examines the impact of green marketing on brand perception and consumer purchase intent across 80 countries from 2006 to 2023. Drawing on data from Bloomberg, Thomson Reuters Eikon, and Sustainalytics, this research employs structural equation modeling and hierarchical linear modeling to analyze the relationships between green marketing expenditure, brand perception, and consumer behavior. The findings reveal that increased investment in green marketing significantly enhances brand perception and purchase intent, with outcomes varying across different economic, cultural, and regulatory contexts. These results highlight the importance of tailoring green marketing strategies to specific regions, providing actionable insights for advertisers aiming to foster brand loyalty through sustainability. Implications suggest that both advertisers and policymakers can strengthen consumer trust and brand loyalty by aligning sustainable marketing efforts with local cultural and regulatory expectations.