Impulse buying behaviour, defined as an unplanned, spontaneous purchase driven by a strong urge to buy, challenges rational consumer decision-making models (Rook, 1987) ^[17]. This systematic literature review synthesises evidence from 65 peer-reviewed studies (1990–2024) to identify antecedents of impulse buying using the Stimulus–Organism–Response (SOR) framework. Antecedents are categorised into psychological, environmental, and demographic factors. Psychological elements such as trait impulsivity, hedonic motivation, and emotional states underpin buying tendencies, while environmental triggers — including store atmospherics, promotional cues, and online design — catalyse purchases. Demographic variables like age, gender, and income influence the likelihood and intensity of impulse buying. The review highlights the dynamic interaction between emotional arousal and situational stimuli in driving purchase decisions. Practical implications include strategic sensory marketing, targeted promotions, and personalised layouts. Future research should address cultural variations, digital platform influences, and ethical considerations in leveraging impulse buying for sustainable marketing practices.