This paper investigates the role of green branding in shaping the sustainable purchasing decisions of Generation Z (born c.1997–2012). Drawing on interdisciplinary literatures in sustainable marketing, consumer psychology, and digital media studies, the study synthesizes recent empirical evidence and theoretical perspectives to identify the mechanisms through which green brand signals (e.g., eco-labels, transparent supply-chain disclosures, corporate social responsibility communication) influence Gen Z attitudes, intentions, and actual purchase behaviour. Attention is given to the mediating roles of trust, perceived authenticity, and green self-identity, as well as moderating influences such as price sensitivity, social norms enacted in social media microcultures, and situational constraints (e.g., availability, convenience). The paper proposes an integrative conceptual model that links green-branding practices to decision-making processes rooted in the Theory of Planned Behavior and contemporary value-attitude-behaviour frameworks. Methodological implications for future empirical work are outlined, prioritizing mixed methods, behavioural field experiments, and trace-data analysis from e-commerce platforms and social networks. The study concludes with managerial recommendations for ethically credible green branding targeted to Gen Z and a research agenda that highlights unresolved questions — notably about greenwashing detection, the effectiveness of third-party verification, and longitudinal change in Gen Z cohorts as they age and gain purchasing power. The paper aims to provide a rigorous, researchable foundation for academics and practitioners seeking to align branding strategies with genuine sustainability outcomes among younger consumers.