Fear of Missing Out (FoMO) is a pervasive phenomenon among college students that may negatively affect the physical and mental health of individuals. Perceived social support, as one of the effective protective factors, can mitigate the harmful effects of FoMO, but few studies to date have examined the potential mechanisms underlying this relationship. The present study conducted an investigation involving 806 college students in China and used scales measuring perceived social support, basic psychological needs, perceived stress and FoMO to explore the relationship between perceived social support and FoMO. Findings indicated that 1) perceived social support was negatively associated with college students’ FoMO; 2) basic psychological needs partially mediated the relationship between perceived social support and FoMO; 3) the mediating role of basic psychological needs is moderated by perceived stress. Further, the study provides some theoretical and practical implications for the prevention of FoMO.