ABSTRACT In this study, we aimed to investigate the relationship between compulsive buying (CB), biological rhythm, impulsivity, and fear of missing out (FoMO). The data in the research was collected from 493 university students using a package of psychological tools including the personal questionnaire, the Compulsive Buying Scale (CBS), Barratt Impulsiveness Scale (BIS-11), Fear of Missing Out Scale (FoMOs), Morningness–Eveningness Questionnaire (MEQ), Sleep Hygiene Index (SHI), and Depression Anxiety Stress Scale-21 (DASS-21). One-way analysis of variance was used to investigate the differences in scales scores across chronotypes, and hierarchical regression analysis to understand the relationships of compulsive buying scores with socio-demographic characteristics and scales scores. Morning-typeindividuals reported lower scores on the CBS, impulsivity, FoMOs, anxiety, and stress than evening-types or neither-types. According to the hierarchical regression analyses, compulsive buyers reported significantly greater levels of impulsivity, depression, anxiety, and fear of missing out. The results showed that evening-type individuals were more likely to compulsive buying behaviors, impulsivity, and FoMO. In conclusion, this study revealed pioneering findings in terms of CB-related factors. It also showed the relationship between consumers’ compulsive buying behavior, and FoMO and the effect of circadian preferences in biological rhythms on this relationship.