Triangling is one of the factors in a better understanding of self-differentiation. University students may develop behavioral addictions to cope with higher exposure to triangling and have lower resilience, resulting in poor self-differentiation. The current study aimed to investigate the mediating role of smartphone addiction and resilience in the relationship between triangling and differentiation of self. The sample consisted of a total of 536 university students, and data were gathered using the Triangular Relationship Inventory (TRI), Differentiation of Self Inventory Short Form (DSI-SF), Smartphone Addiction Scale-Short Version (SAS-SV), Brief Resilience Scale (BRS), and Demographic Information Form. Findings indicated that the path from triangling to smartphone addiction to resilience explained 45% of the variance in differentiation of self. Smartphone addiction has mediated the relationship between triangling and differentiation of self. However, resilience was not a significant mediator in the relationship between triangling and differentiation of self. Strategies (i.e., de-triangling) may help university students overcome SPA. The current study underlies the potential threats associated with triangling on behavioral addictions (i.e., smartphones), in which the risks may increase as resilience levels of university students decrease, resulting in lower self-differentiation.