Background <p>Compulsive buying is a growing behavioral concern not only in Western societies but also in emerging economies. Despite its rising prevalence, limited research has examined the psychosocial antecedents of compulsive buying within non-Western cultural contexts. Addressing this gap, the current study draws on the Stimulus–Organism–Response (S–O–R) framework to explore how loneliness may contribute to compulsive buying through internal psychological mechanisms.</p> Objective <p>To examine whether loneliness predicts compulsive buying behavior among Indian consumers and whether psychological vulnerability and Fear of Missing Out mediate this relationship.</p> Method <p>Using a cross-sectional correlational design, data were collected from 469 Indian participants selected via purposive sampling. Validated self-report measures were administered, and Structural Equation Modeling (SEM) was employed to test the hypothesized mediation model. Informed consent was obtained from all participants prior to data collection.</p> Results <p>The findings revealed that loneliness significantly predicted compulsive buying behavior. Furthermore, psychological vulnerability and Fear of Missing Out partially mediated this relationship. These results highlight that when an individual’s need for belongingness is unmet, it can lead to compulsive buying as a compensatory behavioral response.</p> Conclusion <p>This study advances S–O–R theory by demonstrating that loneliness, a persistent emotional condition arising from societal factors, functions as a stimulus activating psychological mechanisms that drive compulsive buying. It represents one amongst the few empirical examination of loneliness as an S-O-R stimulus in compulsive buying research and the first investigation of dual mediating pathways (psychological vulnerability and Fear of Missing Out) in an Indian context, offering culturally-grounded insights for interventions targeting maladaptive consumer behavior in emerging economies.</p>