This study investigates the factors influencing green purchase behavior (GPB) among millennials in Saudi Arabia, using the Theory of Planned Behavior (TPB) as a theoretical framework. The research aims to develop and test a model that explains the impact of various factors on GPB. A survey was conducted with 1094 students from King Faisal University, and data were analyzed using SmartPLS-3.3.2. The results indicate that green behavioral control (GBC), green environmental awareness (GEA), and green product value (GPV) have positive and significant effects on GPB. In contrast, green product trust (GPT), green price sensitivity (GPS), and green perceived quality (GPQ) do not significantly influence GPB. The study highlights the importance of these factors in shaping millennials' GPB, providing valuable insights for researchers, marketers, and policymakers. Future research should explore these relationships using a broader sample to enhance generalizability. The findings have theoretical, managerial, and policy implications for promoting green products in emerging markets.This study investigates the factors influencing green purchase behavior (GPB) among millennials in Saudi Arabia, using the Theory of Planned Behavior (TPB) as a theoretical framework. The research aims to develop and test a model that explains the impact of various factors on GPB. A survey was conducted with 1094 students from King Faisal University, and data were analyzed using SmartPLS-3.3.2. The results indicate that green behavioral control (GBC), green environmental awareness (GEA), and green product value (GPV) have positive and significant effects on GPB. In contrast, green product trust (GPT), green price sensitivity (GPS), and green perceived quality (GPQ) do not significantly influence GPB. The study highlights the importance of these factors in shaping millennials' GPB, providing valuable insights for researchers, marketers, and policymakers. Future research should explore these relationships using a broader sample to enhance generalizability. The findings have theoretical, managerial, and policy implications for promoting green products in emerging markets.