This study examines the green purchase awareness of Philippine youth consumers and its influence on green purchase intention and, ultimately, their green purchase behaviour. The study used the theory of planned behaviour as a conceptual framework. The research used an online five-point Likert scale questionnaire and gathered data from accounting and business students in the Philippines; data were collected from 923 usable respondents and then validated and analysed using structural equation modelling (SEM). The findings suggest that respondents’ awareness of environmental degradation’s consequences influences green purchase intention and positively mediates green purchase behaviour. The attitudes, norms, and respondents’ perceived behavioural control represent the environmental awareness beliefs; they positively and significantly contributed to green purchase intention, which contributed to green purchase behaviour. The study is original in that it examines the applicability of the theory of planned behaviour in the context of the Philippines, which has legislative backing for environmental awareness among the citizens. It also investigates the extent to which subjective norms can influence personal behavioural control and mediate towards green purchase intention. The findings contribute to the Philippine setting; however, it is extensible with further research on emerging nations that share societal cultures. The data obtained sufficiently explain the phenomenon using the theory of planned behaviour; combining it with Hofstede’s model of societal culture can increase explanatory power for societal-based studies on purchase intention and behaviour. In a high-power distance and collective societal-cultural setting, findings support the argument that environmental awareness contributes to green purchase intention and buyer behaviour. The proactive stance of making the population aware of the environmental effects is noticeable. However, they provide a low-level explanation of their intention to purchase green products and a medium-level explanation of translating purchase intention to purchase behaviour. Hence, we recommend the government review their approach to making people environmentally aware, which measurably translates into green purchasing intention and purchasing behaviour.