With the popularity of food delivery applications in Indonesia, there is a need to promote responsible consumption habits, specifically in mitigating food waste. This study examined the influence of promotion, knowledge, and subjective norms on sustainable food waste behaviour among Generation Z individuals in Indonesia. The study involved an online survey of 561 Generation Z users of meal delivery platforms, with data analysis conducted using Structural Equation Modeling-Partial Least Squares (SEM-PLS) through SMART-PLS 4 software. The study contradicted that promotion and knowledge directly affect food waste reduction behaviour. Promotion can positively impact responsible food waste behaviour when mediated by price consciousness and perceived behavioural control. Knowledge requires attitude and perceived behavioural control to influence responsible food-wasting. It became apparent that subjective norms directly affected responsible food waste and were mediated by attitude. The antecedent variables examined in this study explained a 63.7% variance of sustainable behaviour towards food waste, indicating moderate explanatory power. Promotion conducted by food delivery service applications, accompanied by information and practical strategies to enhance consumers' perceived behavioural control, can increase the likelihood of sustainable food waste behaviour among Generation Z consumers, particularly price-conscious consumers. To foster positive attitudes and subjective norms towards sustainable food waste behaviour, policymakers can incentivize academic institutions, culinary businesses, and influencers to promote food waste reduction.