Low self-esteem has been identified as a risk factor for problematic mobile phone use (PMPU). However, the magnitude of self-esteem’s effect on PMPU varied across different studies. Drawing on the Interaction of Person-Affect-Cognition-Execution model and the response styles theory, this study developed a moderated mediation model to investigate the mediating role of fear of missing out (FoMO) and the moderating roles of ruminative subtypes (i.e., brooding and reflection) in the relationship between self-esteem and PMPU. We conducted a cross-sectional survey among 806 undergraduate students (Mage = 19.35 years, SD = 1.18) using the convenience sampling method. Results showed that self-esteem was negatively associated with PMPU. Mediation analysis revealed that the association between self-esteem and PMPU was mediated by FoMO. Furthermore, moderated mediation analyses revealed that the mediating effect of FoMO was moderated by both brooding and reflection, such that the indirect effect became stronger for individuals with higher levels of brooding/reflection. These findings add to previous research by shedding light on how (i.e., mediation) and under what conditions (i.e., moderation) self-esteem is associated with PMPU and have implications for early prevention and intervention of individual PMPU.