The study explores the effects of knowledge and attitude on the intention to purchase palm oil–related products in Malaysia. Employing a cross-sectional survey design, data were collected from 414 respondents. A moderation analysis using Hayes’ PROCESS macro (Model 1) was conducted to investigate the effects of attitude, knowledge and their interaction on purchase intention. The model was significant (R² = 0.354, F(3,410)=74.81, p<0.001). Results indicate that both attitude and knowledge significantly and positively influence purchase intention. However, the interaction between knowledge and attitude was not significant (p=.139), suggesting that the effect of attitude on intention remains stable regardless of knowledge level. These findings reinforce TPB’s emphasis on attitudinal determinants of behavioural intention, while supporting KAB’s assertion that knowledge can independently influence behaviour. The study provides empirical insights for policymakers, industry actors, and advocacy groups aiming to design more targeted interventions for sustainable palm oil consumption in Malaysia.