Impulsive buying behaviour is capable to boost sales for stores and trigger consumers to buy online. Millennials in Malaysia cannot resist buying impulsively due to the negative consequences of online impulsive buying behaviour in e-commerce. Therefore, uncontrolled online impulsive buying among millennials in Malaysia has resulted in overspending and consequently building high debt. In line with this issue, the objective of this study is to examine the factors influencing online impulsive buying behaviour and the mediating effect of browsing as well as the moderating effect of price dispersion among millennials in Malaysia. Thus, the research framework for this study is developed based on Stimuli-Organism-Response (SOR) Model. This study was conducted using a quantitative approach and 400 individuals who purchased at least once on an online platform and aged between 20 to 43 years old in Malaysia were selected as target respondents and all responses were collected via Google Form. After the data screening process, only 384 responses proceeded to data analysis by Smart-PLS software. The findings indicated that hedonic-based online store attributes, online reviews, and browsing positively affected online impulsive buying behaviour while browsing was positively affected by utilitarian-based online store attributes, hedonic-based online store attributes, and online reviews. Moreover, browsing significantly mediated the relationship between utilitarian-based online store attributes, hedonic-based online store attributes, online reviews and online impulsive buying behaviour. Therefore, this study provides significant insights for retailers, marketers, and online purchase platform providers regarding the elements of hedonic-based online store attributes, online reviews, and mediation of browsing that trigger online impulsive buying behaviour among millennials in Malaysia.